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  • 51.
    Abdullah Asif, Farazee Mohammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Machine and Process Technology.
    Semere, Daniel Tesfamariam
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nicolescu, Cornel Mihai
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Haumann, M.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    METHODS ANALYSIS OF REMANUFACTURING OPTIONS FOR REPEATED LIFECYCLE OF STARTERS AND ALTERNATORS2010In: 7th International DAAAM Baltic Conference"INDUSTRIAL ENGINEERING"22-24 April 2010, Tallinn, Estonia / [ed] R. Kyttner, Estonia: Tallinn University of Technology , 2010, p. 340-345Conference paper (Refereed)
    Abstract [en]

    The Design for Repeatedly Utilization (DFRU) is a proposed conceptto be used in the product realizationprocess to ensure optimum useable life (forinstance in terms of economy, resourceusage, environmental impact etc.) ofproducts or parts of products enablingmultiple lifecycle. In the DFRU approachproducts are restored as new like productsthrough remanufacturing processes. Theterm remanufacturing has been interpreteddifferently by different researchers and theindustries that are involved inremanufacturing business use differentapproaches to remanufacture theirproducts. In this paper the starter motorand alternator of automotives has beenused to demonstrate the novel concepts.The purpose of this paper is to expresswhat remanufacturing means in ourconcept, model their major lifecycleaspects and create a simulation modelfrom it. This is a preliminary work towardsdefining and specifying the processes,methods and design properties in DFRU.The work will be further extended to aholistic business model which can facilitateDFRU approach in an efficient way. Infuture the model will be developed andadopted to create new models for otherproducts appropriate for remanufacturingand eventually DFRU.

  • 52.
    Abed, Kason
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.).
    FEM-analys av torkapparat2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 53.
    Abelin, Sarah
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Investigation of integrated waterlevel sensor solution forsubmersible pumps: A study of how sensors can be combined towithstand build-up materials and improvereliability in harsh environment2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Monitoring water level in harsh environment in order to handle the start and stop function of drainage pumps has been a major issue. Several environmental factors are present, which affect and disturb sensor measurements. Current solutions with mechanical float switches, mounted outside of pumps, wear out, get entangled and account for more than half of all the emergency call outs to pumping stations. Since pumps are frequently moved around, a new sensor solution is needed which can be integrated within the pump house and is able to continuously monitor water level to optimize the operation of the pump and to decrease wear, cost and energy consumption.

    This thesis presents an investigation how different sensor techniques can be combined to improve reliability for monitoring water level and handle the start and stop function of drainage pumps in harsh environment. The main focus has been to identify suitable water level sensing techniques and to investigate how sensors are affected by build-up materials building up on the pump surface and covering the sensor probes. A support vector machine algorithm is implemented to fuse sensor data in order to increase reliability of the sensor solution in contaminated condition.

    Results show that a combination of a pressure sensor and a capacitive sensor is the most suitable combination for withstanding build-up materials. For operating conditions when sensors are covered with soft or viscous build-ups, sensors were able to monitor water level through the build-up materials. No solution was found that could satisfactorily monitor water level through solidified build-up materials.

  • 54.
    Abeywardana, Asela M.A.J.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Solar-Biomass hybrid system for process heat supply in medium scale hotels in Sri Lanka2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study aimed at evaluating and demonstrating the feasibility of using Concentrated Solar Thermal technology combined with biomass energy technology as a hybrid renewable energy system to supply the process heat requirements in small scale industries in Sri Lanka. Particularly, the focus was to apply the concept to the expanding hotel industry, for covering the thermal energy demand of a medium scale hotel.

    Solar modules utilize the rooftop area of the building to a valuable application. Linear Fresnel type of solar concentrator is selected considering the requirement of the application and the simplicity of fabrication and installation compared to other technologies. Subsequently, a wood-fired boiler is deployed as the steam generator as well as the balancing power source to recover the effects due to the seasonal variations in solar energy. Bioenergy, so far being the largest primary energy supply in the country, has a good potential for further growth in industrial applications like small hotels. 

    When a hotel with about 200-guests capacity and annual average occupancy of 65% is considered, the total annual CO2 saving is accounted as 207 tons compared with an entirely fossil fuel (diesel) fired boiler system. The annual operational cost saving is around $ 40,000 and the simple payback period is within 3-4 years. The proposed hybrid system can generate additional 26 employment opportunities in the proximity of the site location area.  

    This solar-biomass hybrid concept mitigates the weaknesses associated with these renewable technologies when employed separately. The system has been designed in such a way that the total heat demand of hot water and process steam supply is managed by renewable energy alone. It is thus a self-sustainable, non-conventional, renewable energy system. This concept can be stretched to other critical medium temperature applications like for example absorption refrigeration. The system is applicable to many other industries in the country where space requirement is available, solar irradiance is rich and a solid biomass supply is assured.

  • 55. Abeyweera, Ruchira
    et al.
    Senanayake, Nihal S.
    Senaratne, Chamindie
    Jayasuriya, Jeevan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. EIT InnoEnergy, Sweden.
    Fransson, Torsten H.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. EIT InnoEnergy, Sweden.
    Capacity Building Through a Web Based Master Degree Programme in Sustainable Energy Engineering2017In: PROCEEDINGS OF 2017 IEEE GLOBAL ENGINEERING EDUCATION CONFERENCE (EDUCON2017), IEEE, 2017, p. 800-805Conference paper (Refereed)
    Abstract [en]

    Open Distance Learning is gaining popularity as a successful alternative for on-campus higher education especially with the emergence of web based platforms which enable the online delivery of courses worldwide. This emerging educational pedagogy can successfully be employed as means of capacity building of the people living in the less fortunate parts of the world where higher education especially at master level are scarce. This paper presents a two-year collaborative master study programme in sustainable energy engineering offered in synchronous with an on-campus study programme conducted by the KTH Royal Institute of Technology of Sweden, to students of Sri Lanka, which was facilitated by the Open University of Sri Lanka. The paper describes the need of such a programme, the format of course delivery and assessment thereof, plus the benefits gained. This programme has produced 72 post graduates in Sri Lanka alone and more than 200 distant postgraduates worldwide in the field of sustainable energy engineering during last 10 years period. In terms of capacity building in the energy sector in Sri Lanka this is considered a great achievement. The experience gained by the local staff in the role of local facilitators who engaged in some of the academic related activities such as evaluation of students' presentation and co-supervision of thesis projects have been greatly appreciated as being additional benefits to the staff in terms of their own academic development and capacity building. Finally, conclusions are made on how remote programmes of study could successfully be delivered to places where such know-how is scarce by adapting appropriate technologies in training personnel at postgraduate level to meet the needs of the industry.

  • 56.
    Abid, Muhammad
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Global Supply Chain Design: Exploring configurational and coordination factors2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis addresses the topic of global supply chain design. One major challenge concerns how to manage the tension between separation and integration pertaining to the localization of business activities. In this regard Ferdows (2008) worked to create two new production network models (rooted production network and footloose production network). Earlier studies have highlighted the choices that are involved in the network of facilities but lack in providing a comprehensive picture in terms of both configurational and coordination factors that govern the design of global supply chain. There is a need for a conceptual model where factors affecting the design process of a global supply chain can be applied. Two main research questions have been addressed in this study. First, exploring and identifying the factors affecting global supply chain design. Second, investigating the factors that influence the position on the spectrum of rooted and footloose supply chain design.      

    A literature review analysis and multi-case studies have been performed for this study in order to explore the factors. The companies were selected in order to reflect upon the two types of network, i.e., rooted and footloose. The primary data were selected through interviews with the managers.

    This study highlighted that there are many factors that affect configurational and coordination decision areas within a global supply chain. This study categorized the factors and the configurational/coordination decision areas with two main competitive priorities, i.e., cost and differentiation in the form of a “conceptual model.” The study also highlighted the factors in a matrix, which showed their position on the spectrum of rooted and footloose network configurations. For instance, the coordination factors that drive towards a footloose network include: high orchestration capabilities, need access to new technology and knowledge, proximity to suppliers, etc. The configurational factors that drive towards a rooted network include: economic stability, proximity to market, concerns for sustainability issues, high transportation cost, need for high proximity between key functions, need for intellectual property rights protection, etc.

  • 57.
    Abid, Muhammad
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.). Högskolan i Gävle, Sweden.
    Relationship between competitive priorities and global supply chain design: A conceptual frameworkManuscript (preprint) (Other academic)
  • 58.
    Abid, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.). Högskolan i Gävle, Sweden.
    Bengtsson, Lars
    Hellberg, Roland
    Dabhilkar, Mandar
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Factors affecting global supply chain design2012Conference paper (Refereed)
    Abstract [en]

    Due to the limited existing knowledge pertaining to the factors which govern localization of operations and capabilities in a global supply chain, the purpose of the paper is to find out which factors and how they jointly affect the design of global supply chains. The relevant literature is reviewed and a concept matrix is developed. Five companies were selected in order to illustrate the issues of global supply chain design. Among them, three companies are considered to have efficient supply chain and less complex products, while the two others are considered to have responsive supply chain and more complex products. The issues discussed with the selected companies cover global sourcing, challenges, technological advancement and issues related to management control. The study identifies about fifty factors that affect global supply chain design, and specifically how theses relate to design decisions on location of factories and production, supplier selection and development, distribution of products and organisation of interfaces along the supply chain. The discrepancies between theory and practice as well as the implications for further research are discussed.

  • 59.
    Abou Jaoudeh, Elie
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Developement of Optimization Method/A Tool for RE applications in Intermittent Grids with focus on Lebanon2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Renewable energy applications require sound design and optimization of life cycle costs because they need upfront investments and as long as possible operating lifetimes are expected. Using modern tools for optimizing designs of grid-tied and autonomous plants allows investors to deploy these technologies while keeping risks within acceptable limits.

    Nevertheless in Lebanon, the grid is intermittent and the most adapted solutions are dual-mode plants that can operate autonomously and with grid-tie. There are no existent simulation models particularly adapted to optimize these applications for such a situation. The objective of this research is to suggest and test a model adapted from commercially available software that can simulate the particular conditions of Lebanon. The studied solution has a PV generator associated with a PV charge controller, lead acid battery, a dual mode inverter, and transfer switchgear and protections. The research successfully met the objective of finding a setup in HOMER 2.68beta for simulating and optimizing a PV-Battery AC plant for an intermittent grid with scheduled blackouts.

    The setup and adaptation in HOMER is made to replicate an existing reference PV-Battery plant at a public school. The measured data from this public school is used to validate the results obtained from the adapted HOMER simulation. The grid is supplied for an average of 12 hours per day at the reference site with a tariff of USD 0.1/kWh.

    After the validation process, a sensitivity analysis is performed to simulate this plant under

    1. Different grid supply hours, 12 and 18 hours of supply daily
    2. Different grid electricity prices, USD 0.1 and 0.1375 /kWh
    3. Simulation of PV plants to meet other load profiles typical of community and municipality building centers

    All the simulations cross matched 20 different PV generator sizes to 7 different battery sizes for 5 different total setups.

    The levelized cost of electricity, COE, is the main parameter used to find the optimum setups, whereas options that shortened the battery life to less than 12 years or couldn’t meet at least 90% of the required yearly load were filtered out. The COE is calculated manually since several corrections related to grid and net-metering limitations are not obtained directly from HOMER.

    The simulated results can serve as a good indicator on how the systems would perform for typical public institutions in Lebanon, given the current conditions, and knowing that the range of this study is limited to small scale institutions with consumption levels less than 30 kWh/day. Storage capacity should also be limited to 100 kWh/day of useful storage, since batteries are not the best option to use for storage capacities higher than the mentioned limit.

    The setup has a great potential for advancement and acts as a first step for Lebanon to have a specialized tool for simulating the performance of PV-battery AC plants optimized for the conditions existing in the country. Future steps could be made to improve and diversify the software to include:

    • irradiation data that come from actual data logging data from other PV sites which are installed around the whole country, almost a 100
    • financial analysis for offsetting private generation with fossil fueled gensets, which is the main backup for electricity blackouts
    • wind turbine simulations, several installations are provisioned to be completed by the end of 2012, and it would be possible to carry out a similar validation process for small wind turbines
    • pollution and other environmental costs
    • value of lost load, “VOLL”, to compare different options in parallel with COE.

  • 60.
    ABOUD, STEPHANIE
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    AL MANDLAWI, LINA
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Vilken påverkan har stora readagar på produktionen inom tillverkande företag?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Major sales days like Black Friday and Cyber Monday are today widely used and established phenomena around the world. During these days, customers are offered unique offers and strong price reductions on products. Periods like these become important for manufacturing companies as they face more demands in terms of high customer expectations and an increased demand for products.

    The purpose of this work is to investigate whether major sales days have an impact on the production within manufacturing companies. More specifically, it is investigated if the production is made more effective ahead of these days and what methods that are used to forecast demand and to avoid potential risks.

    The question is answered by conducting two studies, a literature and a field study. The literature study gives a theoretical basis for the report. The field study contributes with the practical part as it consists of interviews with two well-established manufacturing companies and also a survey for consumers to respond to. This then gives a better understanding of how companies handle major sales days and of consumers demands and expectations.

    Results from interviews shows that companies control their customers, the resellers, in a matter of how many products they should order on these sales days. Thus, they control their own demand which reduced the need to make the production more effective. In case of increased pressure on the production, companies also take other measures such as hiring extra labour. The companies do not consider the fact that they overproduce to be a problem as they are certain the products will be purchased later.

    The main results from the survey shows that the products sought by the customers during major sales days are often sold out. The majority of these customers’ lack understanding of this which indicates that there is a gap between companies supply and customers’ demands and expectations.

    A conclusion was drawn based on an analysis of the field study in relation to the literature. Companies choose to not directly affect their production or make it more effective ahead of major sales days. However, they are affected from an economic point of view as they take costly measures when faster handling within the production is needed. Furthermore, it was concluded that the customers’ actual demands and expectations are not met during these days, which suggests that companies should reevaluate some of their methods and strategies.

  • 61.
    Abrahamsson, Cajsa
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Miljöpåverkan, hälsopåverkan och LCC för direktdrivna kontra växellådsdrivna vindkraftverk med avseende på deras innehåll av jordartsmetaller2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Vindkraftverk med olika magnetiseringsmetoder (elektromagneter eller permanentmagneter) och maskindriftstyper (direktdrift eller växellådsdrift) undersöks i denna rapport, gällande användningen av jordartsmetaller i dessa. I första delen av rapporten studeras miljö- och hälsopåverkan från jordartsmetallindustrin i den kinesiska provinsen Baotou. Detta då Baotou står för en stor del av försörjningen av jordartsmetaller till vindkraftverksindustrin. I den andra delen av rapporten undersöks skillnaderna i livscykelkostnader mellan vindkraftverk med olika generator- och maskindriftsystem. Rapporten innehåller informationssökningar om olika aspekter som berör dessa teman såsom exempelvis olika typer av vindkraftverksgeneratorer på marknaden, miljöpåverkan från olika ämnen i jordartsmineraler, återvinning av jordartsmetaller och processen från jordartsmineral till permanent-magnet. Informationen är främst inhämtad från vindkraftverkstillverkare, tekniska rapporter och artiklar.

    I miljö- och hälsoanalysen blev slutsatsen att den negativa påverkan från jordartsmetallindustrin i Kina var för omfattande för att användningen av jordartsmetaller skulle rättfärdigas ur ett etiskt och miljömässigt perspektiv. Gruvdriften och bearbetningen av jordartsmetaller har lett till stora utsläpp av skadliga ämnen, såsom exempelvis tungmetaller och radioaktivt avfall, i provinsen Baotou. Dessa har gett allvarliga negativa konsekvenser för djur, människor och växtlighet.

    Livscykelkostnaderna för vindkraftverk med olika generatorsystem beräknades med hjälp av LCC-metoden. Slutsatsen blev att det i dagsläget inte skiljde så mycket kostnadsmässigt i valet av maskindrifttyp eller magnetiseringsmetod. Enligt beräkningar ledde användningen av permanent-magneter inte till några ekonomiska fördelar. Istället var det kostnadsförhandlingar och osäkerhet i indata som gav de största kostnadsskillnaderna. Drift och underhållskostnaderna stod för de definitivt största utgifterna och investeringskostnaderna till generatorsystemen för de näststörsta utgifterna.

  • 62.
    Abrahamsson, Erik
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Naval Systems.
    En övergripande studie av undervattensdockning med obemannade farkoster i ubåt A262019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this report, a Systems Engineering work is discussed, where an investigation has been carried out on the possibility of docking an autonomous underwater vessel with the new generation submarine A26. In the work, the focus has been on the early steps of the Systems Engineering discipline. A literature review of existing research and work in the field has been carried out in order to identify

    possible technical solutions accessible today. Stakeholders have been identified and people with key positions in each area have been interviewed to be able to compile the requirement of needs. Based on the needs, abilities that the system needs to meet have been mapped. In order to facilitate the analysis of the docking system, a definition as well as a zoning of the various stages of the docking process have been performed. A description of different technologies for underwater communication is shown and discussed. An evaluation and risk analysis of a docking system has been carried out to illustrate the pros and cons of the various communication technologies during a docking procedure. Finally, two mechanical systems for the final phase of a docking have been compared to each other.

  • 63.
    Abrahamsson, Johan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Danmo, Johan
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    The Stabilizing Spoon: Self-stabilizing utensil to help people withimpaired motor skills2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The technology for assisting people who are functionallychallenged has improved over the recent decades. With today’stechnology, people with Parkinson’s disease can, witha device on their wrist, be able to draw pictures. Humanlimbs lost due to accidents can be replaced with bionic limbsand with help from smartphones, blind people can by audiobe informed what kind of object that appear in frontof them. These are a few examples where technology haseased everyday life for people with impaired functionality.The purpose of this thesis is to analyze how an Arduino microcontrollercan be utilized to help people with impairedmotor skills during their eating process. A prototype of astabilizing spoon was constructed to work under real circumstancesand intended to be a complement for peoplewho are in need of assistance during their eating process.To make this possible, a sensor with gyroscopes combinedwith accelerometers was used to identify which directionthe device’s handle was being tilted, as well as how fastits position was changed. Two servo motors were placedorthogonally to each other to establish a system of two degreesof freedom. With this setup, the spoon was intendedto maintain its spoon bowl in a horizontal position. Experimentalresults of the spoon showed promising performancewith some limitations.

  • 64.
    Abrahamsson, Lars
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Söder, Lennart
    Fast estimation of aggregated results of many load flow solutions in electric traction systems2008In: COMPUTERS IN RAILWAYS XI, WIT Press, 2008, Vol. 103, p. 411-423Conference paper (Other academic)
    Abstract [en]

    Transports on rail are increasing and major railway infrastructure investments are expected. An important part of this infrastructure is the railway power supply system. The future railway power demands are naturally not known for certain. This means investment planning for an uncertain future. The more remote the uncertain future, the greater the amount of scenarios that have to be considered. Large numbers of scenarios make time demanding (some tens of minutes, each) simulations less attractive and simplifications more so. The aim of this paper is to present a fast approximator that uses aggregated traction system information as inputs and outputs. This facilitates studies of many future railway power system loading scenarios, combined with different power system configurations, for investment planning analysis. Since the electrical and mechanical relations governing an electric traction system are quite intricate, an approximator based on neural networks (NN), is applied. This paper presents a design suggestion for a NN estimating power system caused limits on active and reactive power load, i.e., limits on the levels of train traffic.

  • 65.
    Abrahamsson, Magnus
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Optimering av bergtransporter i underjordsgruva2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis project was conducted at LKAB, a mineral group that manufactures and supplies iron ore products. The work was conducted for the company's underground mine in Malmberget and deals with the rock transport from the mine development. Development is the process which prepares new parts of the mine for iron ore mining. The goals of this work was to identify how the rock transport from the mine development is controlled and to quantify potential savings. If possible, improvement suggestions were to be presented. The basis for this study has been collected on the site of the mine in Malmberget through meetings and conversations with staff, own observations and review of internal documents. Details of the rock transport from the mine development have also been collected in the form of freight statistics and price information. To achieve the goals of the study, two different approaches were chosen. To identify how the transport of rock from the mine development is controlled, a process mapping effort was performed. To quantify the potential savings, I have sought the lowest possible transport cost and compared this with the actual outcome. The study shows that there is a gross potential to reduce transportation costs by 3060 kSEK per halfyear, corresponding to approximately 20 % of the total transport cost. Of this amount, underground transports account for 2041 kSEK (13 %) and transports out of the mine account for 1019 kSEK (6 %). However, the study's limitations makes the potential savings for transports out of the mine highly uncertain. If shafts are made available already in the development stage, there will be even further opportunities to reduce costs.

  • 66. Abreu, L. I.
    et al.
    Cavalieri, A. V. G.
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.
    Vinuesa, Ricardo
    KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.
    Henningson, Dan S.
    KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.
    Wavepackets in turbulent flow over a NACA 4412 airfoil2018In: 31st Congress of the International Council of the Aeronautical Sciences, ICAS 2018, International Council of the Aeronautical Sciences , 2018Conference paper (Refereed)
    Abstract [en]

    Turbulent flow over a NACA 4412 airfoil with an angle of attack AoA = 5◦ was analysed using an incompressible direct numerical simulation (DNS) at chord Reynolds number of Rec = 4 · 105. Snapshots of the flow field were analysed using the method of Spectral Proper Orthogonal Decomposition (SPOD) in frequency domain, in order to extract the dominant coherent structures of the flow. Focus is given to two-dimensional disturbances, known to be most relevant for aeroacoustics. The leading SPOD modes show coherent structures forming a wavepacket, with significant amplitudes in the trailing-edge boundary layer and in the wake. To model coherent structures in the turbulent boundary layer, the optimal harmonic forcing and the associated linear response of the flow were obtained using the singular value decomposition of the linear resolvent operator. The resolvent analysis shows that the leading SPOD modes can be associated to most amplified, linearised flow responses. Furthermore, coherent structures in the wake are modelled as the Kelvin-Helmholtz mode from linear stability theory (LST). 

  • 67.
    Abu Zeid, Houda
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Syed, Tanya
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Suitable textile recycling methods for implementation inSweden: A study in mechanical and chemical recycling methods2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report strives to examine the economical, technical and environmental aspects of textileproduction, but mainly textile recycling. Comparisons between natural fibers and syntheticones will be made, comparing both positive and negative aspects. The textile fibers that willbe discussed are cotton, viscose, polyester and lyocell. Furthermore, an analysis of varioustextile recycling technologies currently available and how suited they are for today’s societywill be made. By doing so one can explore the future possibilities and limitations for thedevelopment of textile recycling. A SWOT-analysis will be conducted in order to examinethe possibility to implement one of the recycling techniques in Sweden. The conclusion thatformed from the SWOT-analysis was that the chemical recycling technique is better fitted fora country of Sweden’s nature. Furthermore, in order for Sweden to be able to implement alarge scale recycling system there is a need for development of certain areas, such as sortingtechnologies, collection and general managing of recycled textile fibers. Some furtherconclusions from this study are that:● Greater focus is needed in order to increase the collection of textiles, since thechemical recycling method is the most efficient when it comes to the recycling oflarger volumes of textiles.● The majority of the sorting of textiles should be done automatically to facilitate thehandling of the collection of textiles.● In the beginning one should focus on recycling textiles that only consist of one type offiber, this since the recycling of textiles consisting of more than one type of fiber ismore complex and the technique for it is not yet fully developed.There are two parts to the report. The first part contains an introduction and a description ofthe project’s research questions and mission. The second part is a literature study whichcontains information about different types of textile fibers currently available and how theproduction and recycling of these fibers affect the environment and society as a whole. Theliterature study is followed by a description of the model used in this report and also ananalysis of the final results. An interview conducted with the sportswear company HoudiniSportswear AB can also be found in the literature study.

  • 68.
    Abuasbeh, Mohammad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn (Editor)
    KTH, Superseded Departments (pre-2005), Energy Technology. KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Aquifer Thermal Energy Storage Insight into the future2018Report (Refereed)
    Abstract [en]

    Underground Thermal Energy Storage (UTES) systems, such as Aquifer thermal energy storage(ATES) are used in several countries. The regulation and research on the potential impacts of ATESon groundwater resources and the subsurface environment often lag behind the technologicaldevelopment of an ever-growing demand for this renewable energy source. The lack of a clear andscientifically supported risk management strategy implies that potentially unwanted risks might betaken at vulnerable locations such as near well fields used for drinking water production. At othersites, on the other side, the application of ATES systems is avoided without proper reasons. Thisresults in limiting the utilization of the ATES technology in many occasions, affecting the possibilityto increase the share of renewable energy use. Therefore, further studies to characterizegroundwater resources, performance monitoring and identification of environmental impacts areneeded to understand the advantages and limitations of ATES systems.

    The environmental impact and technical performance of a Low Temperature ATES (LT-ATES)system in operation since 2016 is presented. The system is called Rosenborg and is owned byVasakronan. It is located in the northern part of Stockholm, on a glaciofluvial deposit called theStockholm esker. The ATES system is used to heat and cool two commercial buildings with a totalarea of around 30,000 m2. The ATES consists of 3 warm and 2 cold pumping wells that are able topump up to 50 liters per second.

    Analysis of groundwater sampling included a period of 9 months prior to ATES operation as well asthe first full season of heating and cooling operation. The sampling was conducted in a group ofwells in the vicinity of the installation and within the system. Means of evaluation constituted astatistical approach that included Kruskal-Wallis test by ranks, to compare the wells before and afterthe ATES was used. Then principal component analysis (PCA) and clustering analysis were used tostudy the ground water conditions change before and after the ATES. Aquifer Variation Ratio(AVR) was suggested as mean to evaluate the overall conditions of the aquifer pre- and post- ATES.

    The results showed some variations in redox potential, particularly at the cold wells which likely wasdue to the mixing of groundwater considering the different depths of groundwater beingabstracted/injected from different redox zones. Arsenic, which has shown to be sensitive to hightemperatures in other research showed a decrease in concentration. A lower specific conductivityand total hardness at the ATES well compared to their vicinity was found. That indicates that theyare less subject to salinization and that no accumulation has occurred to date. It is evident that theenvironmental impact from ATES is governed by the pre-conditions in soil- and groundwater. ThePCA and clustering analysis showed very little change in the overall conditions in the aquifer whencomparing the ATES before and after operation. Temperature change showed negligible impact.This can be mainly attributed to the relatively small temperature change (+6 and – 5 degrees) fromthe undisturbed Aquifer temperature which is 10.5°C.

    Performance of Aquifer Thermal Energy Storage (ATES) systems for seasonal thermal storagedepends on the temperature of the extracted/injected groundwater, water pumping rates and thehydrogeological conditions of the aquifer. ATES systems are therefore often designed to work witha temperature difference between the warm side and cold side of the aquifer without riskinghydraulic and thermal intrusion between them, and avoiding thermal leakage to surrounding area, i.e. optimize hydraulic and thermal recovery. The hydraulic and thermal recovery values of the first yearof operation in Rosenorg weres 1.37 and 0.33, respectively, indicating that more storage volume(50500m3) was recovered during the cooling season than injected (36900m3) in the previous heatingseason.

    Monitoring the operation of pumping and observation wells is crucial for the validation of ATESgroundwater models utilized for their design, and measured data provides valuable information forresearchers and practitioners working in the field. After months of planning and installation work,selected measurements recorded in an ATES monitoring project in Sweden during the first threeseasons of operation are reported in this report.

    The monitoring system consists of temperature sensors and flow meters placed at the pumpingwells, a distributed temperature-sensing rig employing fiber optic cables as linear sensor andmeasuring temperature every 0.25 m along the depth of all pumping and several observation wells,yielding temporal and spatial variation data of the temperature in the aquifer. The heat injection andextraction to and from the ground is measured using power meters at the main line connecting thepumping wells to the system. The total heat and cold extracted from the aquifer during the firstheating and cooling season is 190MWh and 237MWh, respectively. A total of 143 MWh of heatwere extracted during the second heating season. The hydraulic and thermal recovery values of thefirst year of operation was 1.37 and 0.33, respectively, indicating that more storage volume(50500m3) was recovered during the cooling season than injected (36900m3) in the previous heatingseason. The DTS data showed traces of the thermal front from the warm storage reaching the coldone. Only 33% of the thermal energy was recovered. These losses are likely due to ambientgroundwater flow as well as conduction losses at the boundaries of the storage volume. Additionally,the net energy balance over the first year corresponds to 0.12 which indicates a total net heating ofthe ATES over the first year. It is recommended to increase the storage volume and achieve morehydraulic and thermal balance in the ATES system. This can enhance the thermal recovery andoverall performance. Continuous monitoring of the ATES is and will be ongoing for at least 3 moreyears. The work presented in this report is an initial evaluation of the system aiming to optimize theATES performance.

    Furthermore, data management and processing tool has been established for the ATES system in Rosenborg. Additionally, a conceptual model of the ATES area has been established. Current andfuture work is focussed on completing a full scale numerical model in FEFLOW and validated themodel (both hydraulically and thermally) with the available monitoring data. Furthermore,establishing recommendations for optimum design and operation of ATES system.

  • 69.
    Abuasbeh, Mohammad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Fault Detection and Diagnosis for Brine to Water Heat Pump Systems2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The overall objective of this thesis is to develop methods for fault detection and diagnosis for ground source heat pumps that can be used by servicemen to assist them to accurately detect and diagnose faults during the operation of the heat pump. The aim of this thesis is focused to develop two fault detection and diagnosis methods, sensitivity ratio and data-driven using principle component analysis.

    For the sensitivity ratio method model, two semi-empirical models for heat pump unit were built to simulate fault free and faulty conditions in the heat pump. Both models have been cross-validated by fault free experimental data. The fault free model is used as a reference. Then, fault trend analysis is performed in order to select a pair of uniquely sensitive and insensitive parameters to calculate the sensitivity ratio for each fault. When a sensitivity ratio value for a certain fault drops below a predefined value, that fault is diagnosed and an alarm message with that fault appears. The simulated faults data is used to test the model and the model successfully detected and diagnosed the faults types that were tested for different operation conditions.

    In the second method, principle component analysis is used to drive linear correlations of the original variables and calculate the principle components to reduce the dimensionality of the system. Then simple clustering technique is used for operation conditions classification and fault detection and diagnosis process. Each fault is represented by four clusters connected with three lines where each cluster represents different fault intensity level. The fault detection is performed by measuring the shortest orthogonal distance between the test point and the lines connecting the faults’ clusters. Simulated fault free and faulty data are used to train the model. Then, a new set of simulated faults data is used to test the model and the model successfully detected and diagnosed all faults type and intensity level of the tested faults for different operation conditions.

    Both models used simple seven temperature measurements, two pressure measurements (from which the condensation and evaporation temperatures are calculated) and the electrical power, as an input to the fault detection and diagnosis model. This is to reduce the cost and make it more convenient to implement. Finally, for each models, a user friendly graphical user interface is built to facilitate the model operation by the serviceman.

  • 70.
    Abuasbeh, Mohammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    ATES SYSTEM MONITORING PROJECT, FIRST MEASUREMENT AND PERFORMANCE EVALUATION: CASE STUDY IN SWEDEN2018In: Proceedings of the IGSHPA Research Track 2018, 2018Conference paper (Refereed)
    Abstract [en]

    Performance of Aquifer Thermal Energy Storage (ATES) systems for seasonal thermal storage depends on the temperature of the extracted/injected groundwater, water pumping rates and the hydrogeological conditions of the aquifer. ATES systems are therefore often designed to maintain a temperature difference possible between the warm side and cold side of the aquifer, without risking hydraulic and thermal intrusion between them or thermal leakage to surrounding area, i.e. maximize hydraulic and thermal recovery. Monitoring the operation of pumping and observation wells is crucial for the validation of ATES groundwater models utilized for their design, and measured data provides valuable information for researchers and practitioners working in the field. After months of planning and installation work, selected measurements recorded in an ATES monitoring project in Sweden during the first three seasons of operation are reported in this paper. The ATES system is located in Solna, in Stockholm esker, and it is used to heat and cool two commercial buildings with a total area of around 30,000 m 2 . The ATES consists of 3 warm and 2 cold pumping wells that are able to pump up to 50 liters per second. The monitoring system consists of temperature sensors and flow meters placed at the pumping wells, a distributed temperature-sensing rig employing fiber optic cables as linear sensor and measuring temperature every 0.25 m along the depth of all pumping and several observation wells, yielding temporal and spatial variation data of the temperature in the aquifer. The heat injection and extraction to and from the ground is measured using power meters at the main line connecting the pumping wells to the system. The total heat and cold extracted from the aquifer during the first heating and cooling season is 190MWh and 237MWh, respectively. A total of 143 MWh of heat were extracted during the second heating season. The hydraulic and thermal recovery values of the first year of operation was 1.37 and 0.33, respectively, indicating that more storage volume (50500m3 ) was recovered during the cooling season than injected (36900m3 ) in the previous heating season. The DTS data showed traces of the thermal front from the warm storage reaching the cold one. Only 33% of the thermal energy was recovered. These losses are likely due to ambient groundwater flow as well as conduction losses at the boundaries of the storage volume. Additionally, the net energy balance over the first year corresponds to 0.12 which indicates a total net heating of the ATES over the first year. It is recommended to increase the storage volume and achieve more hydraulic and thermal balance in the ATES system. This can enhance the thermal recovery and overall performance. Continuous monitoring of the ATES is and will be ongoing for at least 3 more years. The work presented in this paper is an initial evaluation of the system aiming to optimize the ATES performance.

  • 71.
    Abudaff, Anthony
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Möjligheter med betong vid miljöcertifiering: En studie om hur en betongleverantör till byggindustrin kan bidra till en miljöcertifiering2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To steer towards a more sustainable building environment, more and more buildings are certified. The systems requiring input material in the building are Environment Building, BREEAM and LEED. An environmental certification brings together a lot of facts about the building and its sub-materials, and then evaluated according to the criteria of the current environmental certification system. This work aims at examining and assessing what grade or number of points prefabricated concrete elements from Benders byggsystem AB achieve in their respective certification systems.The work has taken advantage of the Concrete Association's reports on how the concrete's characteristics contribute to meeting the requirements of the certification systems. The result is based on material specification and information from Benders together with the Concrete Association's "Sustainable Concrete Construction - Environmental Certification Guide BREEAM / LEED / Environment Building"The result shows which criteria Benders prefabricated concrete elements are able to contribute to the different certification systems. The results of the study show that it is difficult to specifically assess how much an individual building component contributes or what impact it may have on a certification's final grade. All certification methods consider and assess buildings as a whole and in some cases together with its surroundings. The preconditions for environmental certification grades depend on factors beyond the building and its technical solutions. Geographical location, building orientation and surroundings are factors that influence the assessment.Concrete material properties have an indirect impact on many of the aspects of certification systems. In some aspects, such as the amount of waste and local production, there are good conditions for points.Prerequisites in an environmental certification are based on the constructor's / contractor's actions and decisions are partly decisive for the outcome of the certification. In Bender's case it is particularly important to provide full and easily accessible product information of their building elements to facilitate the certification of a building.

  • 72.
    Abukar, Hared
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Al Saati, Firas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.).
    Weda pool cleaner Concept P1002016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to develop a new drivetrain for Wedas current robot pool cleaner W50. Currently, the pump is integrated in the drivetrain which contains only one motor running both wheels and pump. This causes a critical problem affecting cleaning when encountering inclinations in the pool, the robot slides down the slope. To get a better understanding of how the product works, the project group made study visits to Weda. The group documented and observed how the current model and its components are mounted. Interviews were conducted with caretakers and janitors at various municipal swimming pools and hotel pools to get a deeper understanding of how these robot pool cleaners are used and what areas for improvement that exists. The research was used as a foundation for suggestions of new and alternative components for the new concept. The different solutions were then evaluated using a decision matrix to determine which components should be included in the final concept. The work has been carried out in close cooperation with Adigo Drives, which assisted the group with their expertise regarding motors and powertrains. The results culminated in a final concept with a new powertrain and a lower weight than the existing robot.

  • 73.
    Accili, Alessia
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Natural ventilation strategies for nearly – Zero Energy Sports Halls2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In line with the article 9 of the EPDB, member states shall ensure that all new public properties are nearly zero energy buildings (n-ZEB) by December 31, 2018. Sports buildings account for a significant share of the European building stock consumption. More than half of their current energy needs are related to lighting, and a relevant energy use is due to domestic hot water. This work aims to test different energy measures to design nearly zero energy sports halls in Mediterranean climates. Under a holistic approach, the design of the base case sports hall includes the implementation of passive strategies in combination with renewable energy and energy efficient systems in order to meet the n-ZEB conditions. However, a special focus is put on the study of the sports hall ventilation requirements. A natural ventilation system is proposed as an alternative to a traditional mechanical one. The effectiveness of the analyzed ventilation strategies is validated using TRNSYS, a dynamic simulation tool. Therefore, natural ventilation impact on thermal comfort, air quality and energy needs is estimated. A cost effective evaluation is done following the methodology proposed by the European Directive. Additionally, the study is complemented with a short period of measurements in a selected existing facility according to which poor indoor air quality is the main cause of users discomfort during period of maximum occupancy. The obtained results show that the combination of reduction of thermal transmittance of the envelope, optimization of the windows surfaces, façades orientation, introduction of shading devices, installation of energy efficiency systems as LED lamps and use of natural and night ventilation, are advantageous for the reduction of heating, cooling and artificial lighting demand. Overall, consisted primary energy savings are achieved. Moreover, the described strategies ensure indoor thermal comfort, minimizing the period of overcooling and overheating, and provide good air quality conditions for most of the occupied time along one year simulation. Finally, it is verified that the PV system integration positively affects the sports hall performance toward n-ZEB standards.

  • 74. Achi, L. M.
    et al.
    Tibert, G.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Hallgren, M.
    Wanted: A larger, different kind of box2016In: IABSE Congress Stockholm, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment, International Association for Bridge and Structural Engineering (IABSE) , 2016, p. 358-367Conference paper (Refereed)
    Abstract [en]

    To have the ability to "think outside the box" is generally regarded as something positive. At a moment in time when resources are scarce, and the problems facing us are many, innovation and professional excellence becomes a requirement, rather than a matter of choice. At the core of our attempts to come up with new, and better solutions are the digital technologies. Within the structural engineering context, the different types of off-the-shelf packages for finite element analysis play a central role. These "black-box" types of software packages exemplify how user friendliness may have harmful consequences within a field where knowledge and the successful mastery of relevant skills is key, and consequently- ignorance may lead to fatal results. These tools make any effort "venturing outside" difficult to achieve. A technical paradigm shift is called for that places learning and creative, informed exploration at the heart of the user experience.

  • 75.
    Acuna, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Fossa, Marco
    University of Genova.
    Monzó, Patricia
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Numerically generated g-functions for ground coupled heat pump applications2012In: Proceedings of the COMSOL Conference in Milan, 2012Conference paper (Refereed)
    Abstract [en]

    In most ground-coupled heat pump systems, Borehole Heat Exchangers (BHE) represent the typical engineering solution for utilizing renewable energy from the ground. The design of a complex BHE field is a challenging task, due the inherent transient nature of the thermal interaction between the heat exchangers and the surrounding soil. A computation effective method for solving the 3D transient conduction equation describing the ground response to a variable heat load profile is the temporal superposition of pre-calculated temperature response factors or g-functions. In this study Comsol heat conduction models have been developed to calculate g-function values for a borehole field with 64 boreholes. The aim of the investigation is to get an insight on the numerical generation of temperature transfer functions and to some extent provide new information on the Finite Line Source method for analytically generated g-functions as well as on those existing behind existing design software such as EED. The results generally showed a good agreement in lower time ranges. Further in time, the Comsol model revealed to be influenced either by the domain dimensions or the simulation end time.

  • 76.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Bergvärmepumpar Kan Göras Ännu Mer Effektiva2008In: Enegi&Miljö, ISSN 1101-0568, no 3Article in journal (Other (popular science, discussion, etc.))
  • 77.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Characterization and Temperature Measurement Techniques of Energy Wells for Heat Pumps2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ground source heat pumps are a widely used approach to efficiently heat single family houses. In addition to using the ground as a heat source during the winter, it can be used as heat sink and as a free cooling source during the summer. The most common way to carry out the heat exchange with the ground is with the help of energy collectors (borehole heat exchangers) in vertical wells. The quality of the heat exchange depends on the type of collector and on the flow conditions of the circulating fluid. For a complete understanding of the heat transfer performance, it is necessary to carry out careful temperature measurements at research installations and to do a preliminary characterization of the boreholes. These activities might represent a significant cost saving since the system can be optimized based on their outcome. The characterization consists of determining the type of rock and its thermal properties, the groundwater flow at different depths, and the borehole deviation according to the expected position. A comprehensive study about these characterization actions as well as temperature measurement techniques in boreholes using thermocouples and fiber optic technology are described in this report. Study cases from real installations are also presented to exemplify the characterization and measurement methods.

  • 78.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed thermal response tests: New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    U-pipe Borehole Heat Exchangers (BHE) are widely used today in ground source heating and cooling systems in spite of their less than optimal performance. This thesis provides a better understanding on the function of U-pipe BHEs and Investigates alternative methods to reduce the temperature difference between the circulating fluid and the borehole wall, including one thermosyphon and three different types of coaxial BHEs.

    Field tests are performed using distributed temperature measurements along U-pipe and coaxial heat exchangers installed in groundwater filled boreholes. The measurements are carried out during heat injection thermal response tests and during short heat extraction periods using heat pumps. Temperatures are measured inside the secondary fluid path, in the groundwater, and at the borehole wall. These type of temperature measurements were until now missing.

    A new method for testing borehole heat exchangers, Distributed Thermal Response Test (DTRT), has been proposed and demonstrated in U-pipe, pipe-in-pipe, and multi-pipe BHE designs. The method allows the quantification of the BHE performance at a local level.

    The operation of a U-pipe thermosyphon BHE consisting of an insulated down-comer and a larger riser pipe using CO2 as a secondary fluid has been demonstrated in a groundwater filled borehole, 70 m deep. It was found that the CO2 may be sub-cooled at the bottom and that it flows upwards through the riser in liquid state until about 30 m depth, where it starts to evaporate.

    Various power levels and different volumetric flow rates have been imposed to the tested BHEs and used to calculate local ground thermal conductivities and thermal resistances. The local ground thermal conductivities, preferably evaluated at thermal recovery conditions during DTRTs, were found to vary with depth. Local and effective borehole thermal resistances in most heat exchangers have been calculated, and their differences have been discussed in an effort to suggest better methods for interpretation of data from field tests.

    Large thermal shunt flow between down- and up-going flow channels was identified in all heat exchanger types, particularly at low volumetric flow rates, except in a multi-pipe BHE having an insulated central pipe where the thermal contact between down- and up-coming fluid was almost eliminated.

    At relatively high volumetric flow rates, U-pipe BHEs show a nearly even distribution of the heat transfer between the ground and the secondary fluid along the depth. The same applies to all coaxial BHEs as long as the flow travels downwards through the central pipe. In the opposite flow direction, an uneven power distribution was measured in multi-chamber and multi-pipe BHEs.

    Pipe-in-pipe and multi-pipe coaxial heat exchangers show significantly lower local borehole resistances than U-pipes, ranging in average between 0.015 and 0.040 Km/W. These heat exchangers can significantly decrease the temperature difference between the secondary fluid and the ground and may allow the use of plain water as secondary fluid, an alternative to typical antifreeze aqueous solutions. The latter was demonstrated in a pipe-in-pipe BHE having an effective resistance of about 0.030 Km/W.

    Forced convection in the groundwater achieved by injecting nitrogen bubbles was found to reduce the local thermal resistance in U-pipe BHEs by about 30% during heat injection conditions. The temperatures inside the groundwater are homogenized while injecting the N2, and no radial temperature gradients are then identified. The fluid to groundwater thermal resistance during forced convection was measured to be 0.036 Km/W. This resistance varied between this value and 0.072 Km/W during natural convection conditions in the groundwater, being highest during heat pump operation at temperatures close to the water density maximum.

  • 79.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Effektivare Utnyttjande av Energibrunnar för Värmepumpar Undersöks på KTH2010In: KYLA Värmepumpar, Vol. 6Article in journal (Other (popular science, discussion, etc.))
  • 80.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Forskningsprojekt Ska Ge Effektivare Bergvärme2009In: VVS Forum, ISSN 0346-4644, no 1Article in journal (Other (popular science, discussion, etc.))
  • 81.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Framtidens värmesystem med borrhålsvärmeväxlare2011In: Energi&Miljö, ISSN 1101-0568, no 2Article in journal (Other (popular science, discussion, etc.))
  • 82.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Optimera med Rätt Kollektorval2010In: Borrsvängen, ISSN 1103-7938, no 2Article in journal (Other (popular science, discussion, etc.))
  • 83.
    Acuña, José
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Slang intill bergväggen ger effektivare värmeväxling2009In: HUSBYGGAREN, ISSN 0018-7968, no 6Article in journal (Other (popular science, discussion, etc.))
  • 84.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Mogensen, Palne
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed Thermal Response Tests on a Multi-pipe Coaxial Borehole Heat Exchanger2011In: HVAC & R RESEARCH, ISSN 1078-9669, E-ISSN 1938-5587, Vol. 17, no 6, p. 1012-1029Article in journal (Refereed)
    Abstract [en]

    In a distributed thermal response test, distributed temperature measurements are taken along a borehole heat exchanger during thermal response tests, allowing the determination of local ground thermal conductivities and borehole thermal resistances. In this article, the first results from six heat injection distributed thermal response tests carried out on a new, thermally insulated leg type, multi-pipe coaxial borehole heat exchanger are presented. The borehole heat exchanger consists of 1 insulated central and 12 peripheral pipes. Temperature measurements are carried out using fiber-optic cables placed inside the borehole heat exchanger pipes. Unique temperature and thermal power profiles along the borehole depth as a function of the flow rate and the total thermal power injected into the borehole are presented. A line source model is used for simulating the borehole heat exchanger thermal response and determining local variations of the ground thermal conductivity and borehole thermal resistance. The flow regime in the peripheral pipes is laminar during all distributed thermal response tests and average thermal resistances remain relatively constant, independently of the volumetric flow rate, being lower than those corresponding to U-pipe borehole heat exchangers. The thermal insulation of the central pipe significantly reduces the thermal shunt to the peripheral pipes even at low volumetric flow rates.

  • 85.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Mogensen, Palne
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Evaluation of a coaxial borehole heat exchanger prototype2010In: Proceedings of the 14th ASME International Heat Transfer Conference, ASME Press, 2010Conference paper (Refereed)
    Abstract [en]

    Different borehole heat exchanger designs have been discussed for many years. However, the U-pipe design has dominated the market, and the introduction of new designs has been practically lacking. The interest for innovation within this field is rapidly increasing and other designs are being introduced on the market. This paper presents a general state of the art summary of the borehole heat exchanger research in the last years. A first study of a prototype coaxial borehole heat exchanger consisting of one central pipe and five external channels is also presented. The particular geometry of the heat exchanger is analyzed thermally in 2-D with a FEM software. An experimental evaluation consisting of two in situ thermal response tests and measurements of the pressure drop at different flow rates is also presented. The latter tests are carried out at two different flow directions with an extra temperature measurement point at the borehole bottom that shows the different heat flow distribution along the heat exchanger for the two flow cases. The borehole thermal resistance of the coaxial design is calculated both based on experimental data and theoretically.

  • 86.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Mogensen, Preben
    Palne Mogensen AB.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed Thermal Response Test on a U-Pipe Borehole Heat Exchanger2009In: Proc. Effstock 2009, 11th International Conference on Thermal Energy Storage, Stockholm, Sweden: Academic Conferences Publishing, 2009Conference paper (Refereed)
    Abstract [en]

    In a Distributed Thermal Response Test (DTRT) the ground thermal conductivity and boreholethermal resistance are determined at many instances along the borehole. Here, such a testis carried out at a 260 m deep water filled energy well, equipped with a U-pipe borehole heatexchanger, containing an aqueous solution of ethanol as working fluid. Distributed temperaturemeasurements are carried out using fiber optic cables placed inside the U-pipe, duringfour test phases: undisturbed ground conditions, fluid pre-circulation, constant heat injection,and borehole recovery. A line source model is used for simulating the borehole thermal response.Fluid temperature profiles during the test are presented. The results show local variationsof the ground thermal conductivity and borehole thermal resistance along the boreholedepth, as well as a deviation of the latter as compared to the one resulting from a standardthermal response test.

  • 87.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    A novel coaxial BHE: Description and first Distributed Thermal Response Test Measurements2010In: Proceedings World Geothermal Congress 2010, 2010, p. paper 2953-Conference paper (Refereed)
    Abstract [en]

    The thermal performance of a Borehole Heat Exchanger plays a significant role when defining the quality of heat exchange with the ground in Ground Source Heat Pumps. Different designs have been discussed and increased interest on innovation within this field has taken place during the last years. This paper presents the first measurement results from a 189 meters deep novel coaxial Borehole Heat Exchanger, consisting of an inner central pipe and an annular channel in direct contact with the surrounding bedrock. The measurements were taken during a distributed thermal response test using fiber optic cables installed in the energy well. Fluid temperature every ten meters along the borehole depth are presented and compared with similar measurements from a common U-pipe heat exchanger. A unique measurement of the borehole wall temperature in the coaxial collector illustrates how effective the heat transfer performance is through the annular channel.

  • 88.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Comprehensive Summary of Borehole Heat Exchanger Research at KTH2010In: IIR/Eurotherm Sustainable Refrigeration and Heat Pump Technology Conference, Stockholm: KTH Royal Institute of Technology, 2010, p. 69-Conference paper (Refereed)
    Abstract [en]

    A research project that aims at presenting recommendations for improving the COP of ground source heat pump systems by 10-20% through better design of Borehole Heat Exchangers (BHE) is described in this paper. Experiments are carried out with temperature measurements taken in different BHE types during heat pump operation conditions as well as during the thermal response tests. It is also expected to point out methods for having natural fluid circulation in the BHE, i.e. demonstrating that the heat carrier fluid can naturally circulate thanks to temperature induced density differences along the borehole depth, and thereby avoiding the use of electricity consuming pumps. A brief background presenting the most relevant work regarding BHE research around the world is first presented, followed by a comprehensive description of the current research at KTH. Some new measurements and obtained results are presented as an estimation of to what extent the project results have been achieved is discussed. An analysis on how the project results could allow reducing the borehole depth keeping today’s Coefficient of Performance is presented.

  • 89.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Distributed Temperature Measurements on a Multi-pipe Coaxial Borehole Heat Exchanger2011In: IEA Heat Pump Conference, International Energy Agency , 2011, p. 4.19-Conference paper (Refereed)
    Abstract [en]

    The first experiences with a multi-pipe borehole heat exchanger prototype consisting of an insulated central pipe and twelve parallel peripheral pipes are described. Secondary fluid distributed temperature measurements along the borehole depth, being the only ones of its kind in this type of heat exchanger, are presented and discussed. The measurements are carried out with fiber optic cables during heat injection into the ground, giving a detailed visualization of what happens both along the central and peripheral flow channels. The heat exchange with the ground mainly occurs along the peripheral channels and an indication of almost no thermal short circuiting, even while having large temperature differences between the down and upwards channels, is observed.

  • 90.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Experimental Comparison of Four Borehole Heat Exchangers2008In: Refrigeration Science and Technology Proceedings, Copenhagen: International Institute of Refrigeration, 2008, p. SEC09-W1-09Conference paper (Refereed)
    Abstract [en]

    The most common way to exchange heat with the bedrock in ground source heat pump applications is circulating a secondary fluid through a closed U-pipe loop in a vertical borehole. This fluid transports the heat from the rock to the ground source heat pump evaporator. The quality of the heat exchange with the ground and the necessary pumping power to generate the fluid circulation are dependent on the type of fluid and its flow conditions along the pipe. Four different borehole heat exchangers are tested using ethyl alcohol with 20% volume concentration. The fluid temperatures are logged at the borehole inlet, bottom, and outlet. The collectors are compared based on their borehole thermal resistance and pressure drop at different flow rates. The results indicate that the pipe dimensions play an important roll, spacers might not contribute to better heat transfer, and inner micro fins in the pipes improve the performance of the collectors.

  • 91.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    First Experiences with Coaxial Borehole Heat Exchangers2011In: Proceedings of the IIR Conference on Sources/Sinks alternative to the outside Air for HPs and AC techniques, International Institute of Refrigeration, 2011Conference paper (Refereed)
    Abstract [en]

    Some experiences with coaxial borehole heat exchanger prototypes are discussed here. Four different designs are described as they have been part of a research project at KTH: two pipe-inpipe annular designs, one multi-pipe and one multi-chamber design. A special focus is given to two of the prototypes, a pipe-in-pipe design with the external flow channel consisting of an annular cross section and partly insulated central pipe, and a multi-pipe design with twelve parallel peripheral pipes and an insulated central channel. The secondary fluid temperature profiles at low volumetric flow rates are presented for these two prototypes, measured with fiber optic cables during thermal response tests and allowing a detailed visualization of what happens along the heat exchanger depth. It is the first time this is carried out in these types of borehole heat exchangers. The measurements indicate good thermal performance and point at potential uses for these heat exchangers in different ground coupled applications.

  • 92.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Hill, Peter
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Characterization of Boreholes: Results from a U-pipe Borehole Heat Exchanger Installation2008In: Proceedings 9th IEA Heat Pump Conference 2008: Conference Proceedings, Zurich, Switzerland: International Energy Agency , 2008, p. 4-19Conference paper (Refereed)
    Abstract [en]

    Heat exchange with the bedrock for ground source heat pumps is commonly done with the help of U-pipe energy collectors in vertical boreholes. At the moment, there exist many uncertainties about how efficient the heat transfer between the rock and the collector is. For a complete performance analysis of these systems, a 260 m deep water filled borehole is characterized, by measuring the borehole deviation, the ground water flow and the undisturbed ground temperature. Significant attention is devoted to detailed temperature measurements along the borehole depth during operation providing a complete description of the temperature variations in time both for the secondary working fluid and for the ground water. The results show a deviated borehole from the vertical direction without any relevant ground water flow. The undisturbed ground temperature gradient varies from negative to positive at approximately half of the borehole depth. The transient response of the borehole during the heat pump start up is illustrated and it is observed that there does not exist any thermal short circuiting between the down and up-going pipes when the system is in operation.

  • 93.
    Acuña, José
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Khodabandeh, Rahmat
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Weber, Kenneth
    Distributed Temperature Measurements on a U-pipe Thermosyphon Borehole Heat Exchanger With CO22010In: Refrigeration Science and Technology Proceedings, Sydney, Australia: International Institute of Refrigeration, 2010Conference paper (Refereed)
    Abstract [en]

    In thermosyphon Borehole Heat Exchangers, a heat carrier fluid circulates while exchanging heat with the ground without the need of a circulation pump, representing an attractive alternative when compared to other more conventional systems. Normally, the fluid is at liquid-vapor saturation conditions and circulation is maintained by density differences between the two phases as the fluid absorbs energy from the ground. This paper presents some experimental experiences from a 65 meter deep thermosyphon borehole heat exchanger loop using Carbon Dioxide as heat carrier fluid, instrumented with a fiber optic cable for distributed temperature measurements along the borehole depth. The heat exchanger consists of an insulated copper tube through which the liquid CO2 flows downwards, and a copper tube acting as a riser. The results show temperatures every two meters along the riser, illustrating the heat transfer process in the loop during several heat pump cycles.

  • 94. Adamson, G.
    et al.
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Holm, M.
    Moore, P.
    Adaptive robotic control in cloud environments2014In: FAIM 2014 - Proceedings of the 24th International Conference on Flexible Automation and Intelligent Manufacturing: Capturing Competitive Advantage via Advanced Manufacturing and Enterprise Transformation, DEStech Publications Inc , 2014, p. 37-44Conference paper (Refereed)
    Abstract [en]

    The increasing globalization is a trend which forces manufacturing industry of today to focus on more cost-effective manufacturing systems and collaboration within global supply chains and manufacturing networks. Cloud Manufacturing (CM) is evolving as a new manufacturing paradigm to match this trend, enabling the mutually advantageous sharing of resources, knowledge and information between distributed companies and manufacturing units. Providing a framework for collaboration within complex and critical tasks, such as manufacturing and design, it increases the companies' ability to successfully compete on a global marketplace. One of the major, crucial objectives for CM is the coordinated planning, control and execution of discrete manufacturing operations in a collaborative and networked environment. This paper describes the overall concept of adaptive Function Block control of manufacturing equipment in Cloud environments, with the specific focus on robotic assembly operations, and presents Cloud Robotics as "Robot Control-as-a-Service" within CM. © Copyright 2014 by DEStech Publications, Inc. All rights reserved.

  • 95.
    Adamson, Goran
    et al.
    Univ Skovde, Virtual Syst Res Ctr, Skovde, Sweden..
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Moore, Philip
    Univ Skovde, Virtual Syst Res Ctr, Skovde, Sweden..
    Feature-based function block control framework for manufacturing equipment in cloud environments2019In: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588X, Vol. 57, no 12, p. 3954-3974Article in journal (Refereed)
    Abstract [en]

    The ability to adaptively control manufacturing equipment in cloud environments is becoming increasingly more important. Industry 4.0, supported by Cyber Physical Systems and the concept of on-demand, scalable and pay-for-usage resource-sharing in cloud environments offers many promises regarding effective and flexible manufacturing. For implementing the concept of manufacturing services in a cloud environment, a cloud control approach for the sharing and control of networked manufacturing resources is required. This paper presents a cloud service-based control approach which has a product perspective and builds on the combination of event-driven IEC 61499 Function Blocks and product manufacturing features. Distributed control is realised through the use of a networked control structure of such Function Blocks as decision modules, enabling an adaptive run-time behaviour. The control approach has been developed and implemented as prototype systems for both local and distributed manufacturing scenarios, in both real and virtual applications. An application scenario is presented to demonstrate the applicability of the control approach. In this scenario, Assembly Feature-Function Blocks for adaptive control of robotic assembly tasks have been used.

  • 96. Adamson, Göran
    et al.
    Holm, Magnus
    Moore, Philip
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering. Univ Skövde, Sweden.
    A cloud service control approach for distributed and adaptive equipment control in cloud environments2016In: RESEARCH AND INNOVATION IN MANUFACTURING: KEY ENABLING TECHNOLOGIES FOR THE FACTORIES OF THE FUTURE - PROCEEDINGS OF THE 48TH CIRP CONFERENCE ON MANUFACTURING SYSTEMS, 2016, p. 644-649Conference paper (Refereed)
    Abstract [en]

    A developing trend within the manufacturing shop-floor domain is the move of manufacturing activities into cloud environments, as scalable, on-demand and pay-per-usage cloud services. This will radically change traditional manufacturing, as borderless, distributed and collaborative manufacturing missions between volatile, best suited groups of partners will impose a multitude of advantages. The evolving Cloud Manufacturing (CM) paradigm will enable this new manufacturing concept, and on-going research has described many of its anticipated core virtues and enabling technologies. However, a major key enabling technology within CM which has not yet been fully addressed is the dynamic and distributed planning, control and execution of scattered and cooperating shop-floor equipment, completing joint manufacturing tasks. In this paper, the technological perspective for a cloud service-based control approach is described, and how it could be implemented. Existing manufacturing resources, such as soft, hard and capability resources, can be packaged as cloud services, and combined to create different levels of equipment or manufacturing control, ranging from low-level control of single machines or devices (e.g. Robot Control-as-a-Service), up to the execution of high level multi-process manufacturing tasks (e.g. Manufacturing-as-a-Service). A multi-layer control approach, featuring adaptive decision-making for both global and local environmental conditions, is proposed. This is realized through the use of a network of intelligent and distributable decision modules such as event-driven Function Blocks, enabling run-time manufacturing activities to be performed according to actual manufacturing conditions. The control system's integration to the CM cloud service management functionality is also described.

  • 97. Adamson, Göran
    et al.
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering. University of Skövde, Sweden.
    Moore, Philip
    Feature-based control and information framework for adaptive and distributed manufacturing in cyber physical systems2017In: Journal of manufacturing systems, ISSN 0278-6125, E-ISSN 1878-6642, Vol. 143, p. 305-315Article in journal (Refereed)
    Abstract [en]

    Modern distributed manufacturing within Industry 4.0, supported by Cyber Physical Systems (CPSs), offers many promising capabilities regarding effective and flexible manufacturing, but there remain many challenges which may hinder its exploitation fully. One major issue is how to automatically control manufacturing equipment, e.g. industrial robots and CNC-machines, in an adaptive and effective manner. For collaborative sharing and use of distributed and networked manufacturing resources, a coherent, standardised approach for systemised planning and control at different manufacturing system levels and locations is a paramount prerequisite. In this paper, the concept of feature-based manufacturing for adaptive equipment control and resource task matching in distributed and collaborative CPS manufacturing environments is presented. The concept has a product perspective and builds on the combination of product manufacturing features and event-driven Function Blocks (FB) of the IEC 61499 standard. Distributed control is realised through the use of networked and smart FB decision modules, enabling the performance of collaborative runtime manufacturing activities according to actual manufacturing conditions. A feature-based information framework supporting the matching of manufacturing resources and tasks, as well as the feature-FB control concept, and a demonstration with a cyber-physical robot application, are presented.

  • 98.
    Adamsson, Carl
    et al.
    KTH, School of Engineering Sciences (SCI), Physics, Reactor Technology.
    Anglart, Henryk
    KTH, School of Engineering Sciences (SCI), Physics, Reactor Technology.
    An investigation of cross-section geometry effects on the deposition rate in annular two-phase flows with a Lagrangian model2007In: Proceedings - 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12, 2007Conference paper (Refereed)
    Abstract [en]

    The motion of liquid drops in annular two-phase flow in pipes, annuli and subchannels has been investigated with a model based on Lagrangian particle tracking. The results confirm that large drops may deposit by direct impaction. It is also demonstrated that the deposition rate does not differ significantly between pipes and subchannels except for very large drops, which deposit slower in subchannels. Furthermore the Saffman lift force is shown to have a large impact on the results but it is questionable of the standard formulation is applicable to the drops considered here. Finally it is concluded that accurate modeling of high pressure steam-water flows requires a model for drop-drop collisions.

  • 99.
    Adamsson, Carl
    et al.
    KTH, Superseded Departments, Physics.
    Anglart, Henryk
    KTH, Superseded Departments, Physics.
    Dryout predictions in bwr fuel assemblies with spacers2004In: Proceedings of the Sixth International Conference on Nuclear Thermal-Hydraulics, Operation and Safety, 2004Conference paper (Refereed)
    Abstract [en]

    A new spacer model has been implemented into the subchannel code Mona-3 and validated against dryout experiments in various rod bundles with different number of spacers and different spacer designs. The spacer-induced deposition enhancement is captured by proper modeling of the turbulence intensity downstream of a spacer.

    The Mona-3 code with the new spacer model captures spacer effects in a correct manner. Both the effect of the number of spacers and the effect of the spacer design are predicted correctly. In particular, the critical power difference between 24-rod bundles with 6 and with 7 spacers is measured to be larger than the difference between 25-rod bundles with 6 and with 7 spacers. This experimental finding is well captured with the Mona-3 code with the present spacer model.

  • 100.
    Adamsson, Niklas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Malvius, Diana
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Design (Div.).
    Formal and informal roles in complex product development2005In: 2005 IEEE International Engineering Management Conference, Vols 1 and 2, 2005, p. 559-563Conference paper (Refereed)
    Abstract [en]

    This paper illustrates the importance of well-articulated and demarcated roles in complex product development settings. In order to support interdisciplinary knowledge and information sharing formally assigned roles in an organization can be an effective facilitator. It is argued that without comprehensive technical knowledge it is difficult for individuals to identify the relevance and distinctiveness of technical and administrative information.

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