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  • Toma, Johannes
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Ghebreamlak, Sirak
    KTH, School of Industrial Engineering and Management (ITM).
    Num2Braille: A braille calculator2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis attempts to answer how a “braille-only” calculator can be constructed and what needs consideration. An attempt to create such a device has been made. The underlying purpose is the poor selection of braille devices readily available in the market. Braille literacy is very low and the development of easy to use devices that utilize braille actively might encourage the learning of the language.

    A new design for a braille display, which is the display of the calculator, is proposed and a prototype has been built to test it. The first prototype is promising, albeit impractical and quite large. It functions as a calculator but it requires manual calibration upon startup to set the braille wheels to their starting positions.

  • Anderberg, Axel
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Esping, Jonatan
    KTH, School of Industrial Engineering and Management (ITM).
    Kylning av yttersula med hjälp av additiv tillverkning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Innovation through additive manufacturing occurs quickly in today’s industry where rapid prototyping is something that additive manufacturing excels at. However, research is being made to explore the ability for manufacturing components with functional use, where additive manufacturing makes more complex design possible in relation to traditional manufacturing methods. With the environmental problem that occurs in today’s world comes more extreme weather conditions, for example forest fires. With that as a basis, this project has explored the possibility of creating the sole of a shoe with a built-in cooling system, using additive manufacturing, for the purpose of extended work in an environment with a high temperature.

    The requirements put on the sole was that in an environment of high temperature the sole should be able to help reduce temperature inside the shoe itself over the course of an eight-hour workday. Three primary models were analysed in terms of transient temperature as well as load and deformation with the help of CAD and FEM programs, where these three soles were compared to a sole without any form of cooling system. The results show that with the parameters of the project, a greater cooling effect is achieved in two of the three models, compared to a regular sole. Furthermore, there is the potential for continued development of similar models of soles with respect to specific demands in fields such as hiking.

  • Hedberg, Joakim
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Rundström, Per
    KTH, School of Industrial Engineering and Management (ITM).
    Konstruktion av lagerlösning till en TFM generator för vindkraft2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this Bachelor thesis project is the design of a bearing solution for a TFM generator [1], developed by Anders Hagnestål at KTH, suitable for windand wave power. The generator produces inner electromagnetic forces that puts stress on the generators architecture. The bearings will have an essential role in withstanding the force from the electromagnets.

    The most suitable solution was a hybrid axial bearing since the electromagnetic forces are mainly in the axial direction. The hybrid bearing consists of ceramic balls and a steel bearing race, a combination being able to withstand pressures better than axial bearings with steel balls. Ceramic balls are mainly used to avoid electrical discharges between the bearing race and balls. These discharges occur due to switchtransients in the current from the powerelectronic system.

    The placement of the bearing in the generator is of great importance and has to be considered to minimize the displacement of the rotor discs. The project is focused on analyzing the displacement of the rotor disc and the area with greatest pressure in the bearing, this area occurs in the contact point between the ceramic ball and the steel bearing race. Hertzian contact pressure was used for the contact pressure between the ball and the bearing race and the Finite Element Method for calculating the displacement of the rotor disc.

  • Berggren, Filip
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Engström, Jakob
    KTH, School of Industrial Engineering and Management (ITM).
    Autonoma fordon – En jämförelse av tekniker för identifiering av utryckningsfordon2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The demand for safety and effectivity continuously increases within the automotive industry. One way to meet these demands is to achieve a higher level of autonomy, but to achieve the highest levels of autonomy there is a few problems to be solved along the way. This report treats one of these, an autonomous vehicle’s ability to identify emergency vehicles. The report, based on a pilot study, analyses the ITS G5 standard, IEEE 802.11g, Zigbee and mobile networks based on their technological specifications. From the analysis three situations are identified where the technologies are considered limited. These limitations are, but not limited to, reach, latency, data rates and ability to communicate vehicle to vehicle (V2V). The four technologies are then compared by these limitations in a matrix. The result shows that ITS G5 and ZigBee has the best performance by its own but the combination of mobile networks and ITS G5 shows the highest possible performance.

  • Magnusson, Evelina
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Klang, Mattias
    KTH, School of Industrial Engineering and Management (ITM).
    Westlund, Moa
    KTH, School of Industrial Engineering and Management (ITM).
    PET-bottles: From waste to resource2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One of the biggest problems in Guatemala is the handling of plastic waste. Many of the watercourses and rivers in Guatemala are filled with plastic bottles which has a negative impact on both nature and the country’s inhabitants. At the same time, Guatemala is dealing with the problem of segregation between rich and poor. More than half of the population live under the poverty line and in bad conditions. Houses created by thin walls and aluminium roofs are common. In an earlier project an attempt to tackle part of these two issues has been developed by creating roofs our of plastic bottles. The project has been successful but also has some room for improvements.

    In this report these areas of improvements are investigated and analyzed by building a roof for a structure of 9 square meters. This project has a focus on improving the production process and product in order to make them comparable with the aluminium roofing sheets most commonly used today. With tests of possible external impacts that the roof likely will have to withstand, the solidity of the roof has been determined at the same time that evaluation of the process for one person has been compared with building a roof out of aluminium. Since aluminium is expensive and difficult to repair, the roof made out of plastic waste could be good alternative. However it may need an industrial process in order to make it cost and time effective. The production of a roof covering a building of nine square meters need 600 bottles and 41 hours of work.

  • Englund, Felix
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Johansson, Markus
    KTH, School of Industrial Engineering and Management (ITM).
    Anticona, Walter
    KTH, School of Industrial Engineering and Management (ITM).
    Analys av påläggsvetsning av avända bromsskivor2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report investigates Laser Cladding and especially the possibility to coat worn brake discs. A selection of materials are studied with an environmental point of view in focus, the life cycle of the coated brake discs are compared to a standard new gray cast iron brake disc. The program CES Edupack is used for the life cycle analysis and it is completed by formulas of energy consumption and CO2 footprint because not all processes and materials are included in the software. Solid Edge is used to create a CAD model of a typical brake disc to easily exam the volume and weight of the disc as a function of the thickness. The result is laser cladding on worn brake discs saves energy and produces a smaller carbon footprint if the right powders used for cladding are chosen. Laser cladding with stainless steel powders provided the best results with 80.5% savings in energy consumption and 88% in CO2-footprint savings. The laser cladding technique shows clear positive environmental effects.

  • Henningsson, Nils
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Sjöberg, Marcus
    KTH, School of Industrial Engineering and Management (ITM).
    Nivellerande vinschsystem till ett vågkraftverk2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project examines the design possiblilites for a self-leveling winch system for a wave power converter. The chain design for this winch consists of links with limited resistance to torsional shear and bending shear stress and with limited bending capabilities, which requires the winch construction to be able to compensate for angular changes to prevent the chain from breaking.

    Initially several designs were made by evaluating a specification of requirements and by examining the problems facing a winch based wave power converter. These designs were modelled in Solid Edge and evaluated based on complexity, angular steering, servicability and energy requirements for the control systems. The most promising of these designs is composed of a cradle in which the winch drum is mounted. The inclination of the cradle is controlled by electric motors and the rotation is controlled by a rail system with boggies. The design was then further improved upon by utilising ANSYS Workbench to decrease the mass of the design, examining problems related to fatigue failure, and studying stress concentrations. Based on this analysis a set of requirements were specified for a number of key components required for controlling the winch system. Further analysis of the transmission, motor, bearings and energy requirements for the control systems will be needed to evaluate wether the design is profitable to build.

  • Darwich, Anas
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Svanborg, Lovisa
    KTH, School of Industrial Engineering and Management (ITM).
    Bakeleh, Majd
    KTH, School of Industrial Engineering and Management (ITM).
    Felmodsanalys av lastbilskoppling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis aims at finding the failure modes at Scania's clutch system for future selfdriving trucks. The examined components are the ECA (Electronic Clutch Actuator), the fork and the release bearings. The FMEA- tool was used for the mapping the failure modes, their causes and effects. This assessment is made using a 10-grade scale with respect to three parameters: occurrence, degree of severity and detectability. A risk priority number RPN, is calculated by multiplying the aforementioned numbers. The methods that we used are a study trip to SCANIA's facilities, the relevant literature on the subject, and the FEM-analyses of the fork.

    The six most frequent failure modes identified at the release bearing are (fatigue), wear (adhesive and abrasive), corrosion, plastic deformation, electrically induced corrosion and fractures/crack formation. The most common causes for release bearing failures are classified into smearing, assembly, handling, design and runtime circumstances. They include among others exogenous particles (dirt, wear particles), assembly errors, misalignment, insufficient (grease) and excessive loads. All handling of the release bearings is important because release bearing errors have several causes.

    According to experts, the clutch fork is well-designd with a high safety factor. The most common failure mode causes are a result of interactions with neighbouring components e.g. release bearing and ECA. High temperatures increase the stresses and the deformation of the components substantially. Insufficient amount of lubricant in the release bearing is identified as the main reason of failure.

    According to experts from the repair workshop, the ECA unit works smoothly and with a low probability of error.

  • Nazir, Shareq Mohd
    et al.
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway.
    Bolland, Olav
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway.
    Amini, Shahriar
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway ; SINTEF Materials and Chemistry, Trondheim, Norway.
    Full plant scale analysis of natural gas fired power plants with pre-combustion CO2 capture and Chemical Looping Reforming (CLR)2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 114, p. 2146-2155Article in journal (Refereed)
    Abstract [en]

    In this study, first of its kind complete plant scale integration of pre-combustion CO2 capture method with Chemical Looping Reforming (CLR) of Natural Gas (NG), Water Gas Shift (WGS) process, CO2 capture and CO2 compression in a combined cycle power plant has been presented. The CLR consisted of oxidation and fuel reactor. The oxidation reactor oxidizes the metal oxygen carrier with compressed air and produces an oxygen depleted air stream (N-2 stream) as by-product. The fuel reactor reforms the NG with the metal oxide in presence of steam to produce syngas. The syngas is further subjected to WGS and CO2 capture using a-MDEA, to prepare a H-2-rich fuel, which is combusted in the Gas Turbine (GT) system. The heat from cooling of process streams in the pre-combustion CO2 capture method, is used to prepare saturated low pressure steam, fraction of which is used in reboiler to regenerate the amine for CO2 capture, and the remainder is expanded in Steam Turbine (ST) to generate power. The power plant is a combined cycle with two GT, two Heat Recovery Steam Generators (HRSG) and one ST. 12% of air entering the GT is used in the oxidation reactor of CLR, and equivalent amount of N-2 stream is compressed and added as diluent in the GT. The overall process was integrated and analysed at full load conditions. The current process has also been compared with Natural Gas Combined Cycle (NGCC) plant without CO2 capture. The net electric efficiency of the power plant with pre-combustion CO2 capture in this study is 43.1%, which is 15.3%-points less than the NGCC plant without capture. Major energy penalty in the process comes from air compressor, the diluent N-2 stream compressor and due to low degree of process integration to avoid complexity.

  • Smit, Marc Nathaniel
    KTH, School of Industrial Engineering and Management (ITM).
    Elektrisk konstlast till modulator2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ScandiNova Systems AB is a company that develops and produces pulse modulators. For their latest developed modulator, ScandiNova wants an electric load to test it before it is delivered. The customer will use this particular modulator as a part of a cancer treatment machine.

    While working with this project, together with ScandiNova, a requirement specification on how the art load should be is taken. Next, a design is embodied with the CAD software Autodesk Inventor.

    The work resulted in a construction that meets most of the requirements except that it became too expensive. The load will nevertheless be manufactured and ScandiNova has just started a development on a new design.

  • Nazir, Shareq Mohd
    et al.
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
    Bolland, Olav
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
    Amini, Shahriar
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway ; SINTEF Materials and Chemistry, 7034 Trondheim, Norway.
    Analysis of combined cycle power plants with chemical looping reforming of natural gas and pre-combustion CO2 capture2018In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 11, no 1, article id 147Article in journal (Refereed)
    Abstract [en]

    In this paper, a gas-fired combined cycle power plant subjected to a pre-combustion CO2 capture method has been analysed under different design conditions and different heat integration options. The power plant configuration includes the chemical looping reforming (CLR) of natural gas (NG), water gas shift (WGS) process, CO2 capture and compression, and a hydrogen fuelled combined cycle to produce power. The process is denoted as a CLR-CC process. One of the main parameters that affects the performance of the process is the pressure for the CLR. The process is analysed at different design pressures for the CLR, i.e., 5, 10, 15, 18, 25 and 30 bar. It is observed that the net electrical efficiency increases with an increase in the design pressure in the CLR. Secondly, the type of steam generated from the cooling of process streams also effects the net electrical efficiency of the process. Out of the five different cases including the base case presented in this study, it is observed that the net electrical efficiency of CLR-CCs can be improved to 46.5% (lower heating value of NG basis) by producing high-pressure steam through heat recovery from the pre-combustion process streams and sending it to the Heat Recovery Steam Generator in the power plant.

  • Hagelien, Thomas
    et al.
    Radl, Stefan
    Kloss, Christoph
    Goniva, Christoph
    Dahl, Paul Inge
    Nazir, Shareq Mohd
    Fede, Pascal
    Amini, Shahriar
    Porto: A framework for information interchange and multi-scale fluid mechanics simulations2015Conference paper (Refereed)
  • Nazir, Shareq Mohd
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
    Techno-economic analysis of combined cycle power plants integrated with chemical looping reforming and CO2 capture2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The current thesis is a part of the EU FP7 Project titled NanoSim. It focuses on techno-economic analysis of combined cycle power plants with integrated pre-combustion CO2 capture and reforming of Natural Gas (NG). The process consists of reforming of NG, Water-Gas Shift (WGS) reactors, CO2 capture and compression section, and a hydrogen-fueled combined cycle power plant. Two reactor concepts for reforming of NG, Chemical Looping Reforming (CLR) and Gas Switching Reforming (GSR), were considered in this thesis. The respective integrated processes are denoted as CLR-CC and GSR-CC. Both the CLR and GSR involve gas-solid reactions and use a metallic oxygen carrier for the reforming of NG. Exergy analysis carried out shows that CLR has a better thermodynamic potential when compared to the traditional gas-gas partial oxidation process. The design pressure in the CLR was found to be an important parameter in the CLR-CC process that effects the process design and integration. Hence, the CLR-CC process was designed and analysed at different design pressures in the CLR between 5 to 30 bar. The net electrical efficiency of the process increases with an increase in pressure. Anyhow, beyond a pressure of 18 bar, which is also the pressure of the air bleed from the compressor discharge of the selected gas turbine system (F-class gas turbine system in this case), an additional air compressor is required with relatively lower gain in the net electrical efficiency. It was also understood that the reforming and water-gas shift reactions are exothermic, and the heat recovery from these reaction steps to produce steam for the steam cycle in the power plant affects the net electrical efficiency. Different options for heat integration were analysed without modifying the basic design of the Heat Recovery Steam Generator (HRSG). The net electrical efficiency of the CLR-CC process was estimated to be between 40.6 and 46.5%. Producing high-pressure steam instead of low-pressure steam from heat recovery from reforming and water-gas shift reactions, and integrating with HRSG shows a difference of 4%-points in the net electrical efficiency. To carry out the techno-economic analysis of the CLR-CC, a 1D model (includes kinetics of gas-solid reactions and hydrodynamics in the reactor) of the CLR developed in MATLAB was linked with the steady state process models for WGS, CO2 capture and compression section in Aspen Hysys V8.6, and the steady state combined cycle power plant model in Thermoflex component of the Thermoflow Suite V26. The multi-scale model linking approach was established to link the dynamic 1D model of the CLR with the steady state process models for a smooth interaction and flow of process data between them. With the help of this linking approach, a sensitivity study for the effect of air flowrate in the oxidation reactor, steam/carbon ratio in the fuel reactor and the oxidation reactor outlet temperature of the CLR, on the net electrical efficiency was carried out. The levelised cost of electricity (LCOE) of the CLR-CC was also estimated and it was found that it is highly sensitive to the fuel cost followed by the process contingency costs (capital costs accounting for maturity of the process technology). The LCOE of the CLR-CC process lies between 75.3 and 144.8 $/MWh. The CO2 avoidance rates of more than 85% is possible in CLR-CC. Techno-economic assessment of the GSR-CC process was carried out and the net electrical efficiency, CO2 avoidance rates and LCOE were estimated. Sensitivity studies with respect to oxygen carrier utilization and steam/carbon ratio in the GSR is presented in the thesis. The net electrical efficiency of the GSR-CC process lies between 45.1 and 46.2% with CO2 avoidance rates of more than 95%. A case without the WGS in the GSR-CC was also studied and the net electrical efficiency was estimated to be around 47.3%. The LCOE of the GSR-CC process is found to be highly sensitive to the fuel cost and can be as low as 80 $/MWh when the NG price is 4.5 $/GJ-LHV (when compared to 9.8 $/GJ-LHV considered in analysis of GSR-CC). There is still scope to improve and optimize the CLR-CC and GSR-CC processes. Further research on these processes can help in improving the techno-economic behavior and make it competitive against the post-combustion capture Technologies.

  • Lindahl, Amanda
    KTH, School of Industrial Engineering and Management (ITM).
    Industry 4.0 as a Tool for Improvement in a Global FoodSupply-Chain: A Study on how Industry 4.0 can be Implemented in a Global Bakery Group2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Industry 4.0 is at the moment one of the most talked-about topics amongst industry companies. Management teams of discuss the area as something they want to implement, but since it is an ongoing industrial revolution it cannot be implemented straight away. This study is looking into the subject of Industry 4.0 and the identification of nine different technology drivers that a manufacturing company can use as tools in a production environment. However, what is less known is how the tools can be applied to a global company and its different cultures. Because even though Industry 4.0 is about decentralization and giving responsibility to every co-worker, they need to work with a common framework, thus standardization.

    A company that has started to look into Industry 4.0 is Lantmännen Unibake, who is a global bakery group. Therefore, they serve as the case company in this exploratory study where the goal is to conduct a pre-study that gives them, and the food industry, information and guidelines on how Industry 4.0 applies to their industry. Hence, what improvements it can lead to, what tools that will be suitable, and what the prerequisites for a successful Industry 4.0- transformation will be. The method to answer the research question starts with conducting a comprehensive literature study, followed by several interviews around Europe, and ending in an analysis of the current state with help from the literature framework.

    The analysis has ended in a conclusion that there is no single or easy answer to the questions since food industries might vary a lot from one to another. Although, in this case, the answer would be that six out of nine tools would be applicable in a global food-supply-chain, some needing more preparatory work than others. By implementing these tools, companies will see more engaged employees that are prone to take autonomous decisions, more accurate production planning, proactive rather than reactive working ways, fewer defects, and higher customer satisfaction. Regarding the prerequisites for transformation, the answer depends on what tools that are used. But what all cases have in common is that there is a need for aware and engaged employees. Everyone will have to be in on the change, understanding why and how, and what benefits that will come out of it.

    For future studies, it is suggested to look into how maturity models can be applied to these kinds of issues smoothly. The existing maturity models for Industry 4.0 are very complicated and difficult to apply; thus, they would need some development. Another area would be a cost model of the different tools, as well as a comparison of the tools and food regulations.

  • Szima, Szabolcs
    et al.
    Nazir, Shareq Mohd
    Cloete, Schalk
    Amini, Shahriar
    Fogarasi, Szabolcs
    Cormos, Ana-Maria
    Cormos, Calin-Cristian
    Gas switching reforming for flexible power and hydrogen production to balance variable renewables2019In: Renewable and Sustainable Energy Reviews, Vol. 110, p. 207-219Article in journal (Refereed)
  • Hartikainen, Hanna
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Willman, Anna
    KTH, School of Industrial Engineering and Management (ITM).
    Using conventional manufacturing methods for industrialising the production at a start-up company2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This project was initiated in collaboration with a start-up company in the solar cell industry, aiming at producing organic photo voltaic cells in a roll-to-roll process. The company is currently undergoing a transformation from a process validation stage towards a small-scale pilot production, with the goal to reach a steady state production during Q1 2020.

    To achieve their goals, the company wants to increase the degree of industrialisation within their production. The undertaken approach during the project was therefore divided into the following steps:

    1. Identify challenges faced in the production.

    2. Perform a literature review.

    3. Target the challenges by implementing conventional methods used within the manufacturing industry.

    4. Launch a production stress test to get experience from a continuous production flow and to validate the new production status.

    5. Evaluate test results.

    In step 2, the chosen methods were KPIs, stand-up meetings, standardisation, production planning and scheduling, FMEA and flow simulation. Furthermore, general conclusions concerning the applicability and utility of the methods, at this early stage of a production were investigated.

    The production test consisted of having three consecutive rolls going thru the production. When evaluating the test results and the applicability and utility of the chosen methods, following conclusions were drawn:

    • KPIs and production stand-up meetings are considered as useful at this early stage.

    • Standardisation, FMEA and production planning and scheduling are useful, but not necessary at this early stage.

    • Flow simulation is currently not necessary.

    When a company starts its transformation from having a research based small-scale lab production towards an industrialised high-volume production, an additional perspective must be applied. Most important were therefore the change in mind-set, occurring as an effect caused by the synergies arising when all methods were used combined.

  • Hattab, Mazin
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Iljic, Branko
    KTH, School of Industrial Engineering and Management (ITM).
    Analysis of logistics and sales process: A case study of Sika2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In a market where the customers demand and want reliability, there seems to be no one able to meet these demands fully. It is fairly common that customers leave due to insecurities linked with deliveries. This thesis sets out to identify and discuss the factors related to the ability to provide accurate deliveries and how they relate to the company’s current structure.

    Due to the lack of organization and structure of the entire sales process, the employees are forced to apply a kind of improvisation, by taking on problems as they arrive without working proactively to prevent these from ever happening again. Through an in-depth study of the company and their delivery rates, with the help of information collected in interviews, an organizational map was created, which enabled a better understanding of how things should be executed. In addition, a state-of-the-art study was conducted and linked to the current situation at Sika to further increase the theoretical knowledge and to corroborate with the changes necessary for the company to avoid unnecessary costs and work.

    The main findings suggest that Sika must oversee its production processes and how each department handles problems, since the workload is uneven and incorrectly distributed over each department. Sika should also consider alternative transportation methods for deliveries of greater importance. By setting clear boundaries of a department’s obligations and developing standards, in addition to increasing the communication, it will be possible to provide the customer with a satisfactory service and more accurate delivery times.

  • Public defence: 2020-01-09 10:00 F3, Stockholm
    Aguilar, Xavier
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Computational Science and Technology (CST).
    Performance Monitoring, Analysis, and Real-Time Introspection on Large-Scale Parallel Systems2020Doctoral thesis, monograph (Other academic)
    Abstract [en]

    High-Performance Computing (HPC) has become an important scientific driver. A wide variety of research ranging for example from drug design to climate modelling is nowadays performed in HPC systems. Furthermore, the tremendous computer power of such HPC systems allows scientists to simulate problems that were unimaginable a few years ago. However, the continuous increase in size and complexity of HPC systems is turning the development of efficient parallel software into a difficult task. Therefore, the use of per- formance monitoring and analysis is a must in order to unveil inefficiencies in parallel software. Nevertheless, performance tools also face challenges as a result of the size of HPC systems, for example, coping with huge amounts of performance data generated.

    In this thesis, we propose a new model for performance characterisation of MPI applications that tackles the challenge of big performance data sets. Our approach uses Event Flow Graphs to balance the scalability of profiling techniques (generating performance reports with aggregated metrics) with the richness of information of tracing methods (generating files with sequences of time-stamped events). In other words, graphs allow to encode ordered se- quences of events without storing the whole sequence of such events, and therefore, they need much less memory and disk space, and are more scal- able. We demonstrate in this thesis how our Event Flow Graph model can be used as a trace compression method. Furthermore, we propose a method to automatically detect the structure of MPI applications using our Event Flow Graphs. This knowledge can afterwards be used to collect performance data in a smarter way, reducing for example the amount of redundant data collected. Finally, we demonstrate that our graphs can be used beyond trace compression and automatic analysis of performance data. We propose a new methodology to use Event Flow Graphs in the task of visual performance data exploration.

    In addition to the Event Flow Graph model, we also explore in this thesis the design and use of performance data introspection frameworks. Future HPC systems will be very dynamic environments providing extreme levels of parallelism, but with energy constraints, considerable resource sharing, and heterogeneous hardware. Thus, the use of real-time performance data to or- chestrate program execution in such a complex and dynamic environment will be a necessity. This thesis presents two different performance data introspec- tion frameworks that we have implemented. These introspection frameworks are easy to use, and provide performance data in real time with very low overhead. We demonstrate, among other things, how our approach can be used to reduce in real time the energy consumed by the system.

    The approaches proposed in this thesis have been validated in different HPC systems using multiple scientific kernels as well as real scientific applica- tions. The experiments show that our approaches in performance character- isation and performance data introspection are not intrusive at all, and can be a valuable contribution to help in the performance monitoring of future HPC systems.

  • Bohman, Josefin
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Lindell, Johan
    KTH, School of Industrial Engineering and Management (ITM).
    Analys av flödet av KD-stativ på Scania i Oskarshamn2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The cabs are transported on fixtures when leaving the assembly line. Some of the markets that Scania deliveries to are placed far away that leads to an expansive return stream of the fixtures. The solution is to change the fixtures on the cabs that have a final destination too far away to less expansive disposable fixtures. The changing process of the fixtures is a new activity in Oskarshamn and is made manually. This means that there are plenty of room for improvements in the process. Three questions were formulated with communication from Scania to get an idea of the capacity of the KD-unit. The questions that the thesis will answer is:

    • Is there enough capacity at the KD-unit to handle a new stream called market X?

    • Which factors do the capacity influence on?

    • Suggestions of possibilities that could make the management of the ordering and inventory more effective.

    Information was gathered to a current status report of the KD-unit in Oskarshamn. The information was made through observation and interviews besides a literature study with support of some keywords. Market X would increase the volume with 30 % if it were included in the flow today. The factors affecting the capacity are assembly process and storage. The assembly process is the manual change of fixtures; in the current state only 14 % of the capacity is used and if Market X would be included it would increase to 20 %. Storage is depending of the area dedicated for storage, in the report a safety storage is calculated depending on the variation in demand and cycle service level. A test layout is done which eventuate enough storage capacity if implementing Market X. The calculation illustrates how the different factors affect the total storage needed in a cycle and how it could be optimized.

  • Nazir, Shareq Mohd
    et al.
    Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim 7491, Norway.
    Cloete, Jan Hendrik
    Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim 7491, Norway.
    Cloete, Schalk
    Sintef Industry, S.P. Andersens veg 5, Trondheim 7031, Norway.
    Amini, Shahriar
    Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim 7491, Norway ; Sintef Industry, S.P. Andersens veg 5, Trondheim 7031, Norway.
    Techno-economic Comparison Of Combined Cycle Power Plants With Pre-combustion CO2 Capture Via Two Different Reforming Methods: Chemical Looping Reforming And Gas Switching Reforming2018Conference paper (Refereed)
    Abstract [en]

    This paper focuses on the techno-economic comparison of gas-fired combined cycle power plants with CO2 capture and tworeforming methods, chemical looping reforming (CLR) and gas-switching reforming (GSR). The overall processes are denoted asCLR-CC and GSR-CC respectively. The net electrical efficiency of the CLR-CC and GSR-CC is 42.1% and 46.2% respectively.Anyhow, with improvements in the gas turbine configuration, the net electrical efficiency improves by 2.5%. GSR-CC has ahigher CO2 avoidance (>95%). The levelised cost of electricity (LCOE) for CLR-CC is lower than that of GSR-CC for basedload operation of the power plant. Anyhow, GSR-CC provides flexibility in terms of output, electricity or pure H2. The capitalrequirement in the GSR-CC is higher due to the requirement of multiple standalone reactors to maintain a steady flow of thesyngas produced from the GSR. The LCOE of both the processes is sensitive to the fuel cost. Further improvements in the GSRCCprocess can make the process competitive to post-combustion capture.

  • Nazir, Shareq Mohd
    et al.
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
    Cloete, Jan Hendrik
    SINTEF Industry, Trondheim, Norway.
    Cloete, Schalk
    SINTEF Industry, Trondheim, Norway.
    Amini, Shahriar
    Department of Energy and Process Engineering, Norwegian University of Science and Technology, Trondheim, Norway ; SINTEF Industry, Trondheim, Norway.
    Efficient hydrogen production with CO2 capture using gas switching reforming2019In: Energy, ISSN 0360-5442, Vol. 185, p. 372-385Article in journal (Refereed)
    Abstract [en]

    Hydrogen is a promising carbon-neutral energy carrier for a future decarbonized energy sector. This work presents process simulation studies of the gas switching reforming (GSR) process for hydrogen production with integrated CO2 capture (GSR-H2 process) at a minimal energy penalty. Like the conventional steam methane reforming (SMR) process, GSR combusts the off-gas fuel from the pressure swing adsorption unit to supply heat to the endothermic reforming reactions. However, GSR completes this combustion using the chemical looping combustion mechanism to achieve fuel combustion with CO2 separation. For this reason, the GSR-H2 plant incurred an energy penalty of only 3.8 %-points relative to the conventional SMR process with 96% CO2 capture. Further studies showed that the efficiency penalty is reduced to 0.3 %-points by including additional thermal mass in the reactor to maintain a higher reforming temperature, thereby facilitating a lower steam to carbon ratio. GSR reactors are standalone bubbling fluidized beds that will be relatively easy to scale up and operate under pressurized conditions, and the rest of the process layout uses commercially available technologies. The ability to produce clean hydrogen with no energy penalty combined with this inherent scalability makes the GSR-H2 plant a promising candidate for further research

  • Nazir, Shareq Mohd
    et al.
    Department of Energy and Process Engineering, NTNU.
    Ugwu, Ambrose
    Cloete, Jan Hendrik
    Cloete, Schalk
    Zaabout, Abdelghafour
    Amini, Shahriar
    Szima, Szabolcs
    Fogarasi, Szabolcs
    Cormos, Ana-Maria
    Cormos, Calin-Cristian
    Hydrogen: Key to flexible energy systems with CO2 Capture2019Other (Refereed)
  • Nazir, Shareq Mohd
    et al.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Morgado, Joana Francisco
    Norwegian University of Science and Technology, Trondheim, Norway;University of Coimbra, Coimbra, Portugal;Ifavidro Lda, Portugal.
    Andersson, Stefan
    SINTEF Industry, Trondheim, Norway.
    Guo, Zheng Xiao
    University College London, United Kingdom.
    Amini, Shahriar
    Norwegian University of Science and Technology, Trondheim, Norway;SINTEF Industry, Trondheim, Norway.
    Development of nano-structured materials through a novel multi-scale modeling framework for energy conversion with CO2 capture2019Other (Refereed)
  • Krishnakumar Sindhu, Harikrishnan
    KTH, School of Industrial Engineering and Management (ITM).
    Manufacturing Model For The Scaled Production Of NextGeneration Batteries: Evaluation and development of a flexible manufacturing model for the scaled production of next-generation battery technology in existing production facilities for Lithium-ion batteries2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The conventional Li-ion battery technology has been dominating the battery market for over twenty years. Recent years have shown a constant increase in demand from different customer segments for Li-ion batteries. However, the Li-ion batteries pose a series of challenges, which has driven a pursuit for advanced battery technologies that are more efficient and can overcome the drawbacks of Li-ion batteries. The battery industry being highly dynamic, the development and inception of new technologies can happen at a faster rate in the coming years. Hence battery production industries need to be prepared for adapting to any changes induced by the technology change and the requirements from the market. Therefore, the project aims to provide an overview of the advancements happening in the field of battery technology and clearly define a roadmap for the commissioning organization for the coming decade regarding the introduction of new technologies into the market. Also, to provide a production perspective to implement the scaled production of the identified battery technology successfully.

    The research is performed in collaboration with Northvolt AB, a battery manufacturing company, established with a plan to develop the world’s greenest battery cell and build Europe’s largest battery production facility. The research is conducted in two stages. In the first part of the study, with a focus on the European market, a reliable market analysis is performed to identify the technologies with the potential to replace conventional Li-ion battery technology. The second half of the research is focused on developing a product overview for the battery technology that is identified with the potential to replace the conventional Li-ion battery technology in the coming decade and to develop a manufacturing model for the scaled production of the defined technology.

    From the literature study, it is concluded that the solid-state battery technology has the most significant potential to replace the conventional Li-ion battery technology from the market. The study indicated that the solid-state battery technology is expected to achieve 2% EV market penetration by 2030, which shall improve to 12% by 2035. A product overview and a manufacturing model is then developed for the scaled production of all-solid-state batteries in existing production facilities for the conventional Li-ion batteries. Furthermore, the required production infrastructure and the change in business model required with the in-co-operation of new product in the production is briefly discussed.

  • Herrero Cuesta, José Manuel
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Molina Gil, Bernat
    KTH, School of Industrial Engineering and Management (ITM).
    STUDY OF A LEAN MANUFACTURING LABORATORY: IMPROVEMENTS TOWARDS AUTOMATION2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The intention of the Master thesis is to suggest and provide a comprehensive picture of the improvements of a lean manufacturing laboratory installed in Kungliga Tekniska Högskolan (KTH) previously located in Atlas Copco’s facilities.

    This study is initiated with a solid literature review about learning factories, lean philosophy and automated manufacturing. This information, gathered in the literature review section, has allowed the acquisition of the necessary knowledge to first understand the functioning and design of lean laboratories, as well as to internalize the important role that these learning modules play in the development and research of companies. Corporations need these tools to smooth the transition to new, more competitive and efficient production systems. In the same way, as it has been commented, the thesis has the purpose of bringing the lean philosophy closer to the students. For this purpose, some of the most important tools that make up this philosophy have been studied and analyzed, seeking the best way to present it and implement it in the laboratory. Finally, the search for information has focused on the automated manufacturing; the advances in this technology together with the lean philosophy allow reaching higher levels of efficiency on the production and assembly lines. As it has been proven in several articles, automation is the ideal and necessary complement to the lean philosophy, as a preliminary step to industry 4.0. For this reason, automation solutions have also been sought to help the lean lab reaching a higher production stage.

    In the second stage of this work there is an inquiry of the current assembly line, identifying the source of waste in time and resources. In this section the focus is on what the lean laboratory consists of, explaining how it is ran and what is the purpose of it. A detailed explanation of the components of the laboratory is presented along with, the disposition of it and the operations at each workstation. After this analysis, the results of the lean laboratory are shown and there is a following discussion about the results the students got in each stage, what aspects of the assembly were causing wastes and how improve them.

    Finally, after the analysis phase, a proposal of improvements and a posterior discussion of their advantages and drawbacks are discussed, deciding which of the improvements should be put in place in the line. The improvements that are proposed in this work will aim to improve the line in 2 directions: the automation of the line and the inclusion of new lean manufacturing techniques that help the students to understand production and control.

  • Bygge, Mattias
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Strand, Sofie
    KTH, School of Industrial Engineering and Management (ITM).
    Day Master - Redesigning a planning board for people with cognitive disorder2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In assistive technology, there are mainly two different users that needs to be taken into account when developing products. The first, and most important, is the end-user who requires the product in order to function and live a normal life. The second is the support person who, for some products, needs to assist the end-user by preparing it to be used.

    This report presents the master thesis project conducted by Mattias Bygge and Sofie Strand at KTH Royal Institute of Technology in Stockholm. The client was Abilia, a company that research, develop, manufacture and sell assistive technology to people with impairments. This main goal of this project was to redesign a cognitive planning board. The product is used as a visual aid by people who has difficulties in planning daily activities and keeping track of time.

    In order to develop the product in a suitable way, a literature study and interviews with Abilia’s employees laid the foundation for the user studies that were conducted with end-users and support people. Several concepts were generated and five were evaluated against the original product and presented to the company. The two concepts that received the highest ranking, (1) Extra Hours and (2) Extra Hours Bistable, were further investigated and were eventually developed into one single hybrid concept.

    The final design proposal is Day Master, a flexible planning board intended for people with a cognitive impairment that impedes their ability to plan daily activities and keep track of time. The product visually displays time and weekdays by using coloured LED lights, which support people may program without difficulty to fit the end-user’s preference. The amount of hours is changeable with a range of 12-18 hours of daytime and with the remaining hours distributed to night-time.

    The accessories that have been developed for this products are a simple protective cover, and two holders, one for images and one for whiteboard markers. All accessories attaches to the planning board with magnets.

  • Holgersson, Jimmy
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Trydell, Klara
    KTH, School of Industrial Engineering and Management (ITM).
    Pitting Corrosion Evaluation of Post-Weld Cleaning Methods for Stainless Steel Welds2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Welding stainless steel creates an oxide film, heat tint, on the surface and around the joint. It disrupts passivation and influence the corrosion resistance for the material. The result is often a decrease in pitting corrosion resistance for the joint and surrounding area. The heat tint is therefore commonly removed by post weld cleaning. Chemical pickling is traditionally performed on stainless steel welds as a mean to ensure passivation. The method is however hazardous both for the environment and from a safety aspect, because of the harsh chemicals used. It is also increasingly hard to perform on high alloyed stainless steel due to the need for a longer application time and more concentrated chemicals. The problems have led to an interest in alternative methods, for example electrolytical cleaning and laser ablation.

    Two varieties of electrolytical methods and laser ablation have been investigated in comparison to chemical pickling for five differently alloyed stainless steels. They have been ranked based on the critical pitting temperature (CPT) in reference to un-welded and welded samples and further examined microstructurally. An increase in CPT was generally seen for the cleaning methods, compared to the as-welded samples, in some cases obtaining the same CPT as the base material. The difference between the cleaning methods was usually not major and varied depending on material, therefore it is hard to clearly rank one method as superior. Chemical pickling did however tend to result in smaller or fewer pits at CPT compared to the other methods. Process defects or unfavourable structural change caused by welding was ruled out based on microscopy, microstructural analysis and ferrite measurements. SVET analysis was performed on one material for the cleaning methods and an as-welded sample. It was indicated that the sample with heat tint remaining and the laser ablated specimen were prone to pitting in the area closest to the weld. The chemically pickled sample showed some activity in the heat affected zone, while the two varieties of the electrolytical methods were passive. The activity was, however, not investigated for the weld metal.

    It is concluded that chemical pickling can be used as an effective cleaning method, but that an electrolytical method or laser ablation is much faster, less harmful and also tends to facilitate passivation. An electrolytical method or laser ablation might therefore be more beneficial, compared to chemical pickling, depending on the application requirements.

  • Yang, Zhenyu
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Zhao, Zhitie
    KTH, School of Industrial Engineering and Management (ITM).
    Simulation Model to Support Production Transition2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Due to the increase of the market demand, Senseair needs to increase the throughput from 4,000 to 10,000 and to 100,000 in the future. The market is expanding greatly, which requires production line to be improved at a faster pace. To seize the opportunity, effective improvements need to be implemented. But the complexity of the production line makes it particularly difficult to predict the performance of the production line. Hence, computer simulation tool, Plant Simulation, is utilized to simulate the performance of the production line.

    Based on the collected data from the actual production system, a digital twin is built in Plant Simulation. Various experiments are conducted to examine how to increase the throughput in an effective and efficient manner. The result shows the possibilities to reach 10,000 throughput goal but the extreme difficulties to reach 100,000 throughput goal. Consequently, an automated assembly production line is designed based on the manual assembly production line. After tests, the automated production line is proved to be able to meet the higher demand. Improvement suggestions are provided to Senseair for both the current manual assembly production line and the new automated assembly production line.

  • Pimenta de Almeida, Mariana
    KTH, School of Industrial Engineering and Management (ITM).
    Automation of Supply Processes: A Study at Ericsson AB2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the Information and Communication Technology (ICT) industry, the pressure to accelerate the deployment of 5G technology has created a new competitive environment for businesses. This technology not only enables lower latency, but also higher number of connected devices, higher amounts of shared data, and faster. The growing demand from customers is pressuring every stage of the supply chain to become more efficient. In this industry, achieving a short time-tomarket is vital to stay ahead of competitors and position the company as a trend-setter in the eyes of customers. Therefore, it has become necessary to overall shorten lead times and deliver products in a faster way.

    This study was performed in collaboration with Ericsson AB, more specifically in the Ericsson Outbound Supply EMEA. Recent escalations from customers have shown that Ericsson’s ways of working to handle customer purchase orders are not being efficient. In many cases, it is taking longer to process the order than the lead times agreed on the contract with the customer. As a result, this study investigates how automation technologies can improve end-to-end order flows, how these can affect Ericsson as an organisation and its workforce, as well as which factors must be taken into consideration when implementing automation. In order to support the investigation, an analysis of the issues most frequently affecting hardware deliveries to customers was also conducted through the Spiderweb program. The latter is an internal improvement initiative of Ericsson Supply, focused on improving Ericsson’s order handling flows for the Market Area Europe and Latin America.

    The study was based on the following research questions: How can automation technologies help to improve Supply’s performance? How does automation impact the company as an organisation, its culture and workforce? How can the improvement methodology followed in the Spiderweb drive automation discoveries? Qualitative data was primarily collected through meetings with Spiderweb program drivers and 11 interviews held with different stakeholders at Ericsson Supply.

    Conclusively, this study indicates that the four critical factors that will require further developments for automation in Supply to become a reality are: its culture; the establishment of a data-driven organisation; the coordination of different processes and communication between dependent stakeholders; and the technical implementation of automation technology and other tools used locally. It is also concluded that the full potential of automation will only be realised if accompanied by a corresponding development of the workforce, and a clear communication of the strategy from top management. Lastly, the main recommendation to Supply regards the need to standardise order handling processes and simplify order flows, prior to any automation implementation in Supply.

  • Strand, Anna
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Optimization of energy dispatch in concentrated solar power systems: Design of dispatch algorithm in concentrated solar power tower system with thermal energy storage for maximized operational revenue2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Concentrated solar power (CSP) is a fast-growing technology for electricity production. With mirrors (heliostats) irradiation of the sun is concentrated onto a receiver run through by a heat transfer fluid (HTF). The fluid by that reaches high temperatures and is used to drive a steam turbine for electricity production. A CSP power plant is most often coupled with an energy storage unit, where the HTF is stored before it is dispatched and used to generate electricity. Electricity is most often sold at an open market with a fluctuating spot-prices. It is therefore of high importance to generate and sell the electricity at the highest paid hours, increasingly important also since the governmental support mechanisms aimed to support renewable energy production is faded out since the technology is starting to be seen as mature enough to compete by itself on the market. A solar power plant thus has an operational protocol determining when energy is dispatched, and electricity is sold. These protocols are often pre-defined which means an optimal production is not achieved since irradiation and electricity selling price vary. In this master thesis, an optimization algorithm for electricity sales is designed (in MATLAB).

    The optimization algorithm is designed by for a given timeframe solve an optimization problem where the objective is maximized revenue from electricity sales from the solar power plant. The function takes into consideration hourly varying electricity spot price, hourly varying solar field efficiency, energy flows in the solar power plant, start-up costs (from on to off) plus conditions for the logic governing the operational modes. Two regular pre-defined protocols were designed to be able to compare performance in a solar power plant with the optimized dispatch protocol. These three operational protocols were evaluated in three different markets; one with fluctuating spot price, one regulated market of three fixed price levels and one in spot market but with zero-prices during sunny hours. It was found that the optimized dispatch protocol gave both bigger electricity production and revenue in all markets, but with biggest differences in the spot markets. To evaluate in what type of powerplant the optimizer performs best, a parametric analysis was made where size of storage and power block, the time-horizon of optimizer and the cost of start-up were varied. For size of storage and power block it was found that revenue increased with increased size, but only up to the level where the optimizer can dispatch at optimal hours. After that there is no increase in revenue. Increased time horizon gives increased revenue since it then has more information. With a 24-hour time horizon, morning price-peaks will be missed for example. To change start-up costs makes the power plant less flexible and with fewer cycles, without affect income much.

  • Hattab, Mazin
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Iljic, Branko
    KTH, School of Industrial Engineering and Management (ITM).
    Analysis of logistics and sales process: A case study of Company X2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In a market where the customers demand and want reliability, there seems to be no one able to meet these demands fully. It is fairly common that customers leave due to insecurities linked with deliveries. This thesis sets out to identify and discuss the factors related to the ability to provide accurate deliveries and how they relate to the company’s current structure.

    Due to the lack of organization and structure of the entire sales process, the employees are forced to apply a kind of improvisation, by taking on problems as they arrive without working proactively to prevent these from ever happening again. Through an in-depth study of the company and their delivery rates, with the help of information collected in interviews, an organizational map was created, which enabled a better understanding of how things should be executed. In addition, a state-of-the-art study was conducted and linked to the current situation at Company X to further increase the theoretical knowledge and to corroborate with the changes necessary for the company to avoid unnecessary costs and work.

    The main findings suggest that Company X must oversee its production processes and how each department handles problems, since the workload is uneven and incorrectly distributed over each department. Company X should also consider alternative transportation methods for deliveries of greater importance. By setting clear boundaries of a department’s obligations and developing standards, in addition to increasing the communication, it will be possible to provide the customer with a satisfactory service and more accurate delivery times.

  • Thiman, Filip
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Jonathan, Björkman
    KTH, School of Industrial Engineering and Management (ITM).
    Operational excellence through partnering with subcontractors in ground engineering industry2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Construction in Sweden has got a low productivity compared to other manufacturing industries. The construction industry is deeply fragmented and consists of many small companies. The large construction companies are largely dependent on subcontractors. This paper aims to provide answers to how a larger construction company can handle subcontractors in order to achieve higher productivity. The study is carried out in collaboration with JM Entreprenad AB who are involved in ground engineering and foundation work. The study is divided into two questions are to be answered.

    1. What effect can be accomplished trough longer supplier relations with subcontractors?

    2. Is there any correlation between the number of suppliers and a projects outcome?

    The choice of method to answer the first question is a extensive literature study, questionnaire survey, interviews and site visits. The second question is answered though an empirical study based on book documentation of inputs and expenses from projects carried out.

    Collaborating more closely with selected subcontractors receives support in literature and is in line with accepted production principles and is beneficial for increasing productivity. Areas that would primarily benefit from closer work with subcontractors:

    • Standardization work.

    • Eliminate waste and avoid sub-optimization.

    • Quality control and repeatability.

    • Counteract ’hostile contracting’ and opportunistic thinking.

    • Improve experience feedback.

    It is not possible, in this study, to give a clear answer based on literature findings that the construction industry would benefit from closer cooperation and a defined number of subcontractors. One reason may be the lack of data from projects defined by far-reaching collaborations.

    There is in this setup no correlation between the number of subcontractors and a project’s wine margin. However, this may depend on how the empirical study was conducted och analyzed.

  • Tollander, Sofia
    KTH, School of Industrial Engineering and Management (ITM).
    A Value Proposition for Cloud-Enabled Process Planning2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To stay competitive in today’s fast-paced market, manufacturing companies must shorten their time-to-market and decrease their costs by efficiently utilizing their resources. Here, improved software and better software integration throughout the product realization process is considered to be a key enabler.

    The aim of this thesis work has been to investigate the current workflow in design and process planning to outline a cloud-based application to support these activities. Pains and bottlenecks in these workflows have been identified through interview and field studies at six Swedish manufacturing companies of different sizes, in different industries, and with different operational models.

    The major areas of improvement were identified whereof one them, the initial activity of understanding customers’ needs, was decided to further focus on. From receiving a request for quotation from the customer to acceptance of an order, the following time-consuming activities were recognized: understand and discuss design intent as well as suggest possible design changes to improve manufacturability, analyze and review 2D drawings and 3D models, and develop order quotations.

    In this thesis work, a mock-up prototype has been put forward. The intent with this is to bridge a gap that has been identified through the mapping between manufacturers needs and functionality of available CAD/CAM software and the identified areas of improvement from the workflow investigations.

    The proposed solution, as presented in the mock-up prototype, has been validated together with three of the studied companies. At its current state, further improvements and validations are needed. Nevertheless, if further developed, it has the potential to create value within the entire manufacturing value chain.

  • Högström, Johan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Hammer, Monica
    Södertörns Högskola.
    Stjernberg, Mats
    Nordregio.
    Lidmo, Johannes
    Nordregio.
    Exploring Processes of Contextualization and Concretization: Navigating the Road to Realization in Local Level Spatial Planning Practices in Stockholm, SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    New governance approaches challenge prevailing statutory planning practices since urban development initiatives emanate not only from central and local government. This study explores the road to realization, i.e. how local planning practices organize the process of assessing the appropriateness of urban development initiatives. The results show how planning organizations face a variety of interrelated organizational and procedural conditions and choices that make planning situations unique and contextual. To deal with this contextuality, planners use processes of contextualization and concretization to relate an initiative to its environment and to gradually transform an initiative to a final land use design.

  • Högström, Johan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Balfors, Berit
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Sustainability Assessment and Management.
    Hammer, Monica
    Södertörns Högskola.
    Brokking, Pieter
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Organization of municipal planning processes for enhanced sustainability: examples from peri-urban areas in Stockholm, SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    This study analyzes how local planning processes are organized and the possibilities to consolidate sustainability issues in urban development. The results show that the municipalities use different approaches, and that municipalities engage with challenges associated with different phases of the urban development planning process. The case study identifies three main lessons related to the enhancement of sustainability in the planning process. First, sustainability issues need to be brought into the center for consideration at an early stage of the planning process. Second, to have non-technical sustainability issues, which are often in the periphery of the planning process, become embedded in planning process, there is a need to evaluate existing rules for process participation. Third, to enhance sustainability in municipal spatial planning, there is a need to complement the existing project-based approach to planning with an ongoing learning process in which practitioners from different levels can exchange experiences and expectations regarding the existing institutional setting.

  • Public defence: 2019-12-18 10:00 F3, Stockholm
    Pålsson, Sara
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Numerical Analysis, NA.
    Boundary integral methods for fast and accurate simulation of droplets in two-dimensional Stokes flow2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Accurate simulation of viscous fluid flows with deforming droplets creates a number of challenges. This thesis identifies these principal challenges and develops a numerical methodology to overcome them. Two-dimensional viscosity-dominated fluid flows are exclusively considered in this work. Such flows find many applications, for example, within the large and growing field of microfluidics; accurate numerical simulation is of paramount importance for understanding and exploiting them.

    A boundary integral method is presented which enables the simulation of droplets and solids with a very high fidelity. The novelty of this method is in its ability to accurately handle close interactions of drops, and of drops and solid boundaries, including boundaries with sharp corners. The boundary integral method is coupled with a spectral method to solve a PDE for the time-dependent concentration of surfactants on each of the droplet interfaces. Surfactants are molecules that change the surface tension and are therefore highly influential in the types of flow problems which are considered herein.

    A method’s usefulness is not dictated by accuracy alone. It is also necessary that the proposed method is computationally efficient. To this end, the spectral Ewald method has been adapted and applied. This yields solutions with computational cost O(N log N ), instead of O(N^2), for N source and target points.

    Together, these innovations form a highly accurate, computationally efficient means of dealing with complex flow problems. A theoretical validation procedure has been developed which confirms the accuracy of the method.

  • Nazir, Shareq Mohd
    et al.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Cloete, Jan Hendrik
    Sintef Industry, Trondheim, Norway.
    Cloete, Schalk
    Sintef Industry, Trondheim, Norway.
    Amini, Shahriar
    Norwegian University of Science and Technology, Trondheim, Norway ; Sintef Industry, Trondheim, Norway.
    Efficient hydrogen production with CO2 capture using gas switching reforming (GSR): techno-economic assessment2019In: Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS), 2019, p. 635-644Conference paper (Refereed)
    Abstract [en]

    Hydrogen is identified as one of the clean energy carriers in the future energy scenario. This work presents a process to produce low cost hydrogen with CO2 capture using gasswitching reforming (GSR). The process steps include GSR, water-gas shift, purehydrogen recovery in pressure-swing adsorption process and CO2 and hydrogencompression trains. The overall process, denoted as GSR-H2, produces 99.999% purehydrogen with >96% CO2 capture. In this study, GSR-H2 is compared economically with the conventional steam-methane reforming (SMR) plant that produces hydrogenwithout CO2 capture. GSR-H2 produces 10% more hydrogen when compared to theSMR plant, but consumes significant imported electricity. The cost of hydrogenproduced from the GSR-H2 and SMR plant is similar (1.67 €/kg-H2) with a CO2 tax of only 20 €/ton, even with GSR-H2 being a near zero emission plant. In a future energy scenario where the CO2 emission tax is high and the electricity price is low, GSR-H2will significantly outperform the conventional SMR plant.

  • Laurenti, Rafael
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development. HERUS Laboratory for Human Environment Relations in Urban Systems, EPFL Swiss Federal Institute of Technology Lausanne, 1015 Lausanne, Switzerland.
    Singh, Jagdeep
    The International Institute for Industrial Environmental Economics (IIIEE), Lund University, 221 00 Lund, Sweden.
    Cotrim, Joao
    ISCTE-IUL Business School, University of Lisbon, 1649-004 Lisbon, Portugal.
    Toni, Martina
    Department of Business Studies, University of Roma Tre, 00154 Roma, Italy.
    Sinha, Rajib
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    Characterizing the Sharing Economy State of the Research: a Systematic Map2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 20Article in journal (Refereed)
    Abstract [en]

    The sharing economy is an emerging niche for innovation capable of disrupting established socio-technical and economic regimes. Because of this potential to cause radical changes in a wide array of domains, research in multiple disciplines addressing various aspects entailing this phenomenon is proliferating. In this emerging body of literature, the understanding and framing of the sharing economy are often different. Without knowledge about the current state of the research related to the sharing economy, delineating research trends, gaps, and needs for directing effectively primary research are not possible. This study aimed to synthesize the state and distribution of existing publications related to the sharing economy in multiple disciplines. We used the systematic mapping technique to scope, identify, and classify the publications at a fine level of granularity. We reviewed 589 journal articles (published from 1978 to 2017), and 454 met the selection criteria. The journal articles reviewed were published in 284 different journals. Intriguingly, 15 journals published five to 13 publications each and 221 journals had a single article about the topic. Journals belonging to the subject areas “business, management and accounting” (42.1%) and “social sciences” (35.2%) published more than 70% of the reviewed publications. Accommodation (19.8%) and car and ridesharing (17.2%) were the two most prominent sectors; 50.2% of the publications addressed C2C transactions (10.6% B2C, 24.4% more than one type); 62.3% were about accessing resources, and 5.1% concerned transfer of ownership (i.e., second-hand or donation); and 19.2% covered access and transfer of ownership simultaneously. While empirical studies were the majority (53.1%, when comparing with conceptual ones), qualitative approaches were most common (51.5% against 24.9% quantitative and 17.4% mixed methods). Literature review (22.9%), survey (13.2%), case study (7.3%) and interview (7%) were the most frequently used methods. User behavior (26.4%), business models and organizational aspects (22.7%), institution and governance system (18.7%), conceptualization matters (17%), and sustainability evaluation (15.3%) are research clusters identified from a grounded approach. The link between user behavior and net environmental impacts of sharing options was the largest gap found in the research needing attention from a sustainability perspective. Accordingly, multidisciplinary investigations quantifying behavioral root causes, magnitude, and likelihood of environmental rebound effects using real-world data are strongly encouraged.

  • Danelia, David
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Gonzalez Allendes, Nanitza
    KTH, School of Industrial Engineering and Management (ITM).
    Automatic Whiteboard Eraser: A systematic and automated process2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The whiteboard is a tool being used in several different facilities around the world. However, erasing the ink off the board can be unnecessarily time consuming and distracting. The purpose of the project was therefore to create a demonstrator to automate the process with a few restrictions. The demonstrator was required to be light enough and small enough to be handheld. In addition, the demonstrator needed to function and work properly on a magnetic surface.

    To conceptualize the purpose a demonstrator was built with an iterative process and thereafter programmed to get a systematic movement. It utilized continuous servo motors, IR-sensors and a 3-axis gyroscope and an accelerometer in combination with 3D-printed components.

    The final prototype turned out to function properly but could be improved as its erasing properties are not working as one could expect from a finished prototype.

  • Mshothola, Angelina
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Girlesa Lizcano Quintero, Maryori
    KTH, School of Industrial Engineering and Management (ITM).
    Corporate Entrepreneurship - Transferring Innovations into the Main Organization: A Case Study in the Context of the Telecommunications Industry2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis explores the topic of Corporate Entrepreneurship in large organizations with regards to how innovations are transferred from an Innovation Department into a receiving Business Unit. It aims to understand this topic by identifying what challenges are common barriers to this transfer process. It also identifies the causes of these challenges. Finally, this thesis establishes what suitable approach can be adapted to address these challenges.

    To answer these concerns, this research takes a deductive research approach by conducting a qualitative, empirical research through semi-structured interviews within a large Nordic telecommunication company. It also includes, benchmarking against two examples of companies that have developed solutions to overcome similar challenges. This qualitative methodology involves analyzing the interview and benchmarking results in comparison with literature, to confirm or disprove previous research.

    From the findings, eight categories of common challenges are discovered which are rooted within the innovation strategy of incumbent companies. Based on this research, a framework is developed as an approach to address the challenges of transferring innovations from an Innovation Department into a receiving Business Unit. As contribution to this field of study, this thesis highlights how multiple academic theories such as Corporate Entrepreneurship, Innovation Management and Innovation Strategy can be synthesized to collectively address these challenges. This is done by proposing a solution that is adaptable for different incumbent organizations. The proposed framework uses a stage-gate process that progresses when certain criteria agreed between an Innovation Department and a receiving Business Unit, are fulfilled. This agreement is based on the extent to which the criteria for each stage-gate is achieved in order to transfer ownership of the innovation solution.

  • Berntsen, Jens
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Bäckström, Jonathan
    KTH, School of Industrial Engineering and Management (ITM).
    Viktiga komponenter i e-lektioner.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Throughout the ages, major technical breakthroughs have on several occasions been integrated into education, but each new technology has its strengths and weaknesses. With the development of the computer and its increased accessibility to the public, the amount of available teaching material (Clark & Mayer, 2016) and the number of students who are studying courses in e-learning has increased (Statista, 2015). E-learning is then, according to Clark & Mayer’s (2016) definition, learning that takes place through a digital medium.

    One possibility that arises with e-learning is that there are many ways of presenting material. One problem that arises then is to know which components should be used to create good elessons that promote student learning. The aim of the study is to identify which components are important for content creators to use in e-lessons and then, based on these components, develop an editing tool designed to create new e-lessons.

    To identify the appropriate components, a thematic analysis was first carried out on e-lessons from a learning platform in order to examine which components the instructional designers use to present material. Qualitative interviews were conducted to capture the instructional designers’ ideas and opinions regarding the components. These ideas and opinions were used together with the results of the thematic analysis to make didactic choices about which components are suitable for use in e-lessons. The development of the editing tool was done by creating multiple prototypes and discussing them with the instructional designers to determine the appearance of the components in the tool.

    From the thematic analysis, 7 themes emerged with a total of 22 sub-themes. The results of the didactic choices were 12 main components, for instance: text, image, video, quiz and examples. The editing tool that was built contains all 12 main components, but some components still lack some parts described in the didactic choices. The tool was evaluated by instructional designers who thought it worked but had some shortcomings that needs to be addressed.

    For the instructional designer to be able to use the editing tool to create and publish new elessons on the platform, the tool needs to be integrated into the platform, all components need to be completed and user experience improved.

  • Kuniholm, Johanna
    KTH, School of Industrial Engineering and Management (ITM).
    Kunimodellen: En utbildningsmodell för signaltekniker på Roslagsbanan2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To be able to find and solve signal failures in Roslagsbanan in Stockholm, it is important that the maintenance technicians working with the signalling system has the right knowledge and feel confident with how the system works. One part of the safety system at Roslagsbanan is called ATC (automatic train control) which sends information to the train driver about where adjacent trains are located and how upcoming signals, switches and road crossing barriers are set. The ATC also interferes by applying brakes if the driver does not stop at a stop signal. To make troubleshooting of the ATC system more efficient, the company maintaining the signalling system, tracks and power supply at Roslagsbanan, Strukton Rail AB, would like to further educate their maintenance technicians. They want a model for training sessions in troubleshooting that can be used with training equipment and can be applied to other technical systems. To create this model my research questions were ”What could a pedagogical model for troubleshooting education on the safety system ATC at Roslagsbanan look like? How does the model affect the participants’ activity compared to other education sessions in the railway business?”. It was important to Strukton that participants should be active and cooperate with each other during the session. After reading about the sociocultural perspective on learning, accelerated learning and workplace learning and also conducting interviews with two technicians at Strukton and two teachers in other parts of the railway business to hear what they value as good education, I created an educational model for inservice training of the signalling system ATC, named the Kuni model.

    The model is based on participants solving troubleshooting cases together. An education session starts with an overview of the system that can vary in detail depending on the participants’ previous knowledge. Then the participants solve cases by discussing in groups and agreeing on a plan on how they should troubleshoot, and then try their plan on the test equipment where the error is planted. Depending on their need for education and the available time, they can get a different number of cases on different levels, but the cases should try to cover as many of the system’s components as possible. At the end of the session there is time for reflection where the participants tell each other what they have learnt. To get a measurable indication of if the participants have learned anything, they fill out a questionnaire just before and just after the education with questions on how confident they feel troubleshooting the different components. Two such sessions were held with the Kuni model, each with two cases to solve, for a total of seven participants. To measure participant activity, I filled out an observation form for 20 minutes per hour where I registered whether each participant had spoken or not for 40 intervals of 30 seconds each, which I also did at two other training sessions that signalling technicians attend to get a control group. Additionally, I conducted group interviews with the participants after the sessions to see what they thought of the model and what could be improved.

    The results from the interviews show that the participants were content and thought it was a good model to work with, but that some technical information about the test equipment that exists in the real world was missing. They also wanted more detailed information in the initial overview with focus on, among other things, why the ATC system exists. The participants’ selfestimated confidence in troubleshooting increased after the session, but they were not significantly more active during training with the Kuni model than the control groups. The Kuni model itself did not change very much between sessions. The results should however only be seen as indications due to the small number of participants, the participants not necessarily being representative for the whole group and since all people interviewed knew me when I interviewed them.

  • Altayy, Fares
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Schmied, Fredrik
    KTH, School of Industrial Engineering and Management (ITM).
    Stimulering av kritiskt tänkande och kollaboration i en programmeringsorienterad fysik- och matematiklaboration: en fallstudie med elever från programmet Tekniskt basår (KTH)2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work aims to develop a proposal for educational material in the form of a programming-oriented Physics and Mathematics lab. The target group is mainly students from the second semester in the Technical Preparatory Year program (KTH), but also students of equivalent knowledge level (for example, students in the upper secondary school- natural science program).

    The lab was designed to create opportunity for students to:

    1) apply critical thinking,

    2) demonstrate collaboration,

    3) increase subject understanding.

    The proposed educational material comprises computational physics, where a nonlinear differential equation derived from a mathematical pendulum is solved using numerical methods. The exercises in the lab were formulated with critical thinking in mind and pair programming was used as the context for collaboration. In this paper 1) and 2) were investigated in an educational setting with students from the second semester of the Technical Preporatory Year (KTH). The conversations of four student groups were recorded and a content analysis was performed on the transcriptions of the audio recordings. A pattern matching method was used to strengthen the conclusions. Based on the results of the research project, we found that the theoretical proposition that the construction of the laboratory work has contributed to the collaboration and application of critical thinking by the students, has been strengthened.

  • Fall, Emmeli
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Kirsch, David
    KTH, School of Industrial Engineering and Management (ITM).
    Koden först: Utformning av ett induktivt introduktionsmoment i programmering på Tekniskt basår med bakgrund i identifierade svårigheter2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In 2018, programming became an integral part of mathematics education in Sweden. However, the choice of how to integrate it with the curriculum remains a decision of the teacher. Consequently, teachers at KTH’s Technical Preparatory Year announced a master’s degree project aiming to design programming labs in mathematics for students attending the program during 2018/2019. The degree project was reformulated to focus on introducing programming without the mathematical context.

    The aim of this master thesis was to pinpoint earlier students’ difficulties during the introductory course in programming of their engineering program at KTH. These difficulties would later be the basis of the programming introduction for the current Technical Preparatory Year students. A review of the research literature on the learning of programming identified a number of common areas of concern. In order to collect data to identify our prior students’ difficulties a survey was designed. The data collected in the survey was then categorized through a thematic analysis.

    The results indicated seven themes of difficulties: abstract, complex, theory, work procedure, programming courses, new and miscellaneous. The results are similar to those found in prior categorizations of programming difficulties. Taking these themes into consideration, a suggestion of the content for the introduction was presented based on ideas from inductive learning and problem based learning.

    Future research should focus on determining whether the introduction dealt with the difficulties and what the effects were. Furthermore, future research could develop the material for the introduction, in particular how students are assessed.

  • Friefeldt, William
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Gullberg, Philip
    KTH, School of Industrial Engineering and Management (ITM).
    Nätcoaching som ett komplement till lösningsförslag: En undersökning av en ny digital lärmiljö genom undersökande relation2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The digital and technical development of the world have been large-scale and people’s day-today life has changed immensely the last century. In contrast, the Swedish school system has not been seeing the same rapid technical development. As students’ results in mathematics are declining an approach to battle this trend can be to apply this technological development on students’ studies in mathematics. Therefore, this thesis sought to ease students’ mathematics studies by creating a digital learning environment. By combining workedexamples with online coaching the environment was created through the platforms Mathleaks and TalkMath. Then examine how online one-to-one coaching works in this environment. It also sought to analyse how students perceive this teaching environment and if it can be used as a complement to worked-examples. The environment was created based on pedagogical theories such as Vygotsky's sociocultural perspective, coach theories, synchronous communication as well as theory around one-to-one online coaching. Two methods were used to gather data. First, the conversations were automatically stored in a database. Secondly, a survey was used to gather the students’ opinion of the teaching environment. The framework Relationship of Inquiry was used to analyse all conversations between students and coaches. Students were chosen from an upper secondary school in the ages of 15-18 where one of the authors worked. Results indicated that the teaching environment that was created was a good complement to worked-examples. The environment was shown to help student’s knowledge progression. This shows that digital teaching environments can be a valuable addition for students when studying mathematics.

  • Stasolla, Vincenzo
    KTH, School of Industrial Engineering and Management (ITM).
    Numerical analysis of aerodynamic damping in a transonic compressor2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Aeromechanics is one of the main limitations for more efficient, lighter, cheaper and reliable turbomachines, such as steam or gas turbines, as well as compressors and fans. In fact, aircraft engines designed in the last few years feature more slender, thinner and more highly loaded blades, but this trend gives rise to increased sensitivity for vibrations induced by the fluid and result in increasing challenges regarding structural integrity of the engine. Forced vibration as well as flutter failures need to be carefully avoided and an important parameter predicting instabilities in both cases is the aerodynamic damping.

    The aim of the present project is to numerically investigate aerodynamic damping in the first rotor of a transonic compressor (VINK6). The transonic flow field leads to a bow shock at each blade leading edge, which propagates to the suction side of the adjacent blade. This, along with the fact that the rotating blade row vibrates in different mode shapes and this induces unsteady pressure fluctuations, suggests to evaluate unsteady flow field solutions for different cases. In particular, the work focuses on the unsteady aerodynamic damping prediction for the first six mode shapes. The aerodynamic coupling between the blades of this rotor is estimated by employing a transient blade row model set in blade flutter case. The commercial CFD code used for these investigations is ANSYS CFX.

    Aerodynamic damping is evaluated on the basis of the Energy Method, which allows to calculate the logarithmic decrement employed as a stability parameter in this study. The least logarithmic decrement values for each mode shape are better investigated by finding the unsteady pressure distribution at different span locations, indication of the generalized force of the blade surface and the local work distribution, useful to get insights into the coupling between displacements and consequent generated unsteady pressure. Two different transient methods (Time Integration and Harmonic Balance) are employed showing the same trend of the quantities under consideration with similar computational effort. The first mode is the only one with a flutter risk, while the higher modes feature higher reduced frequencies, out from the critical range found in literature. Unsteady pressure for all the modes is quite comparable at higher span locations, where the largest displacements are prescribed, while at mid-span less comparable values are found due to different amplitude and direction of the mode shape. SST turbulence model is analyzed, which does not influence in significant manner the predictions in this case, with respect to the k-epsilon model employed for the whole work. Unsteady pressure predictions based on the Fourier transformation are validated with MATLAB codes making use of Fast Fourier Transform in order to ensure the goodness of CFX computations. Convergence level and discrepancy in aerodamping values are stated for each result and this allows to estimate the computational effort for every simulation and the permanent presence of numerical propagation errors.

  • Wikberg, Elena
    KTH, School of Industrial Engineering and Management (ITM).
    Catalytic Upgrading of Fast Pyrolysis Bio-oil Using Zeolites2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Fast pyrolysis bio-oil is considered as a possible source for production of liquid bio-fuels and bio-chemicals enabling the necessary transition to a renewable energy system. In this Master’s thesis work the upgrading of fast pyrolysis bio-oils with Fluid Catalytic Cracking (FCC) conversion process at industrially relevant conditions is studied using Fluid Catalytic Cracking Micro Activity Test (FCC MAT) unit at RISE ETC in Piteå, Sweden. The study is focused on evaluating the process in terms of production of value-added products including petrochemical materials, such as propylene and benzene, toluene, xylene (BTX), and petroleum range liquid biofuels. The evaluation of the process was based on the upgraded products yield and quality characterized by the chemical composition of collected liquid and gas samples with regards to several influencing factors including origin of the bio-oil, addition of ZSM-5 zeolite to the commercial catalyst and FCC operation parameters, such as reaction temperature, catalyst to oil (CTO) ratio and ZSM5 zeolite catalysts acidity. Several analytical methods were applied for characterization of both feedstock and products, including GC MS analysis and determination of the boiling range distribution of the liquid products by simulated distillation. The results of this work showed that the process of upgrading pure pyrolysis bio-oil was challenging and required further studies to develop a practical operating process. While the process of co-feeding of the pyrolysis bio-oil with commercial FCC fossil feedstock was determined as feasible at industrially relevant conditions. Catalytic conversion of co-fed pyrolysis bio-oil at the ratio of 20/80 resulted similar petrochemical products to commercial fossil feedstock with full deoxygenation of pyrolysis bio-oil. Moreover, the results showed that high catalytic reaction activity conditions with high reaction temperature along with the use of ZSM-5 zeolite were favored for maximizing the BTX and gasoline range products.

  • Johnson S, Rejish Lal
    KTH, School of Industrial Engineering and Management (ITM).
    Thermal gas radiation modelling for CFD simulation of rocket thrust chamber2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Methane and oxygen are a promising propellant combination in future rocket propulsion engines mainly due to its advantages like reusability and cost reduction. In order to have a comprehensive understanding of this propellant combination extensive research work is being done. Especially, for reusable rocket engines the thermal calculations become vital as an effective and efficient cooling system is crucial for extending the engine life. The design of cooling channels may significantly be influenced by radiation. Within the framework of this thesis, the gas radiation heat transfer is modelled for CFD simulation of rocket thrust chambers and analysed for the 𝐶𝐻4/𝑂2 fuel combination. The radiation is modelled within ArianeGroup’s in-house spray combustion CFD tool - Rocflam3, which is used to carry out the simulations.

    Radiation properties can have strong influence for certain chemical compositions, especially 𝐶𝑂2 and 𝐻2𝑂 which are the products of the 𝐶𝐻4 and 𝑂2 combustion. A simplified gas radiation transport equation is implemented along with various spectral models which compute the gas emissivity for higher temperature. Also, Rocflam-II code which has an existing gas radiation model is used to compare and validate the simplified model. Finally the combination of the convective and radiative heat transfer values are compared to the experimental test data. In contrast to the previously existing emissivity models with a certain temperature limit, the model used here enables the inclusion for the total emissivity of 𝐶𝑂2 and 𝐻2𝑂 for temperatures up to 3400 K and hence more appropriate for hydrocarbon combustion in space propulsion systems.

    It turns out that the gas radiation is responsible for 2-4% of the total heat flux for a 𝐶𝐻4/𝑂2 combustion chamber with maximum integrated temperature of 2700 K. The influence of gas radiation would be greater than 4% respective of the integrated temperature. Gas radiation heat flux effects are higher in stream-tube combustion zone compared to the other sections of the thrust chamber. The individual contribution of radiative heat flux by 𝐶𝑂2 was noted to be 1.5-2 times higher than that to 𝐻2𝑂. It was shown that the analytically derived simplified expression for gas radiation along with the various spectral models had reasonable approximation of the measured radiation. The estimated radiation was correct to the measured radiation from the Rocflam-II model for a temperature range of 400-3400 K.

  • Wahlgren, Lars Fredrik
    KTH, School of Industrial Engineering and Management (ITM).
    Evaluation of CFD Methods for Prediction of Total Temperature and Total Pressure Distribution in Gas Turbines2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis work was performed as a collaboration between the Royal Institute of Technology in Stockholm and Siemens Industrial Turbomachinery in Finspång. It was undertaken with the purpose of investigating the use of CFD methods in ANSYS CFX to predict flow mixing in gas turbines.

    The results were evaluated against experimental data gathered as part of an international collaboration; The FACTOR project. The experimental data investigated were total temperature and total pressure at nozzle guide vane inlet and outlet.

    The results thus focus mainly on nozzle guide vane inlet and outlet due to the nature of the available experimental data.

    The distribution of these parameters was also investigated in the NGV flow channel and on the vane surface, but it is appreciated that any conclusions drawn from these results are speculative in nature due to the lack of experimental data. Any conclusions drawn must be placed in perspective of the evaluation of NGV inlet and outlet, for which experimental data is available.

    The focus was on the mixing of the total temperature and total pressure in a nozzle guide vane connected to a combustion chamber simulator.

    The methods investigated were RANS-SST, SBES and LES-WALE. The main conclusions are that the inclusion of a combustion chamber mesh and thus simulating the CC flow increases the accuracy of the nozzle guide vane results for RANS-SST simulations. It is also observed that in general the SBES and LES-WALE method yield highly similar results under the investigated circumstances, and that both these methods show a general improvement over the RANS-SST method.

  • Pettersson, Marcus
    KTH, School of Industrial Engineering and Management (ITM).
    Cooling Potential of Methane in Rocket Nozzle Cooling Channels: A Conjugate Heat Transfer Analysis2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of hydrocarbons as fuel in rocket propulsion has been of great interest to the aerospace industry in recent years. Specifically, natural gas with a high content of methane has taken the interest of several actors, among them Sweden-based GKN Aerospace who in collaboration with KTH Royal Institute of Technology have started the MERiT project. In this project, the potential of methane as a fuel is explored through conjugate heat transfer analysis of a cooling channel geometry on a test rig. The goal is partly to find what the cooling potential of the methane is, and partly to determine the risks of thermal cracking occurring in the cooling channel.

    This report aims to provide a CFD analysis of the behavior of a test rig developed in earlier stages of the project. The analysis is to be used to provide design points that real experiments can be based upon. Studied behaviors include limitations regarding overheating, choke in the cooling channel and efficiency of the rig. In addition to this, the fluid temperature is studied in order to provide an estimate of which design points provide the highest potential risk of thermal cracking. In experiments, this potential risk is to be evaluated and explored in order to judge the viability of methane as a fuel.

    From this thesis a database of design points has been built regarding two potential channel geometries with different alloy materials. The post process and gathering of data are designed in such a way that specific behaviors can be monitored depending on a specific input. Inputs include mass flow, heat flux, inlet temperature and outlet pressure of the test rig. These were parametrized such that 243 specific design points could be examined for each channel geometry. Concluding this thesis, it was found that 131 of the cases examined for the first channel geometry were within the realm of being useful, and that a few cases fall within the realm of being at risk for coking. The risk for choke in the cooling channel is apparent at high mass flows and low pressures. The efficiency is heavily tied to heat flux and inlet temperature but shifts to be more dependent on Reynold’s number when cases with unintended behavior are filtered out.