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  • 1. Begun, S. V.
    et al.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Nizhyn Gogol State University, Ukraine .
    Modeling and simulation of the high-temperature jet's penetration behaviours in a pool of volatile coolant2010In: Applied computer science, 2010, p. 173-178Conference paper (Refereed)
    Abstract [en]

    Theoretically the problem considered belongs to the thermalhydraulics of the multiphase systems, while practically the problem is of paramount interest for many applications in the nuclear power safety (e.g. modeling of the severe accidents scenario), chemical technology, geology, volcano, etc. For instance, present operation of the nuclear power plants (NPP) still considered by many countries as the energy source of the highest priority requires strict substantiation of the nuclear power safety. Now the second-generation nuclear reactors are replaced by the third-generation reactors, which are necessary at the change to the operable reactors. And the passive protection systems against severe accidents at NPP capable for work even under the conditions of the complete NPP de-energizing must work perfectly under any severe accident scenario, to localize emergency and prevent spreading of the radioactive fuel melt (high-temperature corium melt) outside the containment. As it is stated in the International (IAEA) regulatory documents by the nuclear power safety, the successful construction and operation of the passive protection systems against severe accidents at NPP must prevent outlet of any radioactive materials outside the containment of the NPP. Therefore the detail precise modeling and simulation of the diverse thermal hydraulic processes with the "hypothetical severe accidents" scenario is of paramount interest and this paper considers one type of such problems for high-temperature jet penerating the volatile coolant pool.

  • 2. Begun, S. V.
    et al.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Nizhyn Gogol State University, Ukraine .
    Peculiarities of the local abnormal heat transfer due to non-linear heat conductivity and their influence on the steam (gas) non-isothermal filtration through the particles layer2010In: Applied Computer Sciences, 2010, p. 179-184Conference paper (Refereed)
    Abstract [en]

    The 2-D model of a non-stationary, non-isothermal steam (gas) filtration through a monospherical particle layer with internal heat generation is considered and analyzed with the particular emphasis on the non-thermal steam/particles local equilibrium. The real non-linear properties of the steam (gas) and particles, as well as the influence of the impermeable medium surrounding the permable layer are taken into account. Boundary-value problem for the complex multiphase system of the steam (gas) flow and the layer of particles is formulated both in the dimension and then in dimensionless forms and both are discussed. The thermal hydraulic problem is solved numerically using the effective finite-difference fractional time-step method earlier develod by one of the authors. It is shown that some initial thermodynamic perturbations in the system, which are always present in such kind of systems, may cause the phenomenon of local abnormal steam heating (mainly due to non-linear heat conductivity of the steam having power-law character by temperature). This phenomenon was first revealed for such non-linear boundary-value problems in a modeling of geothermal systems 25 years ago. Then it was revealed for the severe accidents scenario both theoretically and experimentally. The phenomenon of local abnormal heating may cause some temperature escalation in a specific spatial region of the system, which is of paramount interest for many modern industrial and natural processes because it differs dramatically from the linear case, which is conventionally considered in a similar systems without taking into account the real non-linear processes.

  • 3. Gharakhanlou, J.
    et al.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Konoval, O. V.
    Development and investigation of the mathematical models for potentially hazardous nuclear power objects with deviated arguments2013In: WSEAS Transactions on Applied and Theoretical Mechanics, ISSN 1991-8747, E-ISSN 2224-3429, Vol. 8, no 4, p. 241-257Article in journal (Refereed)
    Abstract [en]

    The paper is devoted to one of the problems of system analysis for nuclear power plants (NPP) in touch with the modelling and simulation of the potentially hazardous objects in nuclear power safety including severe accidents at the nuclear power plants. Development and implementation of the mathematical models for analysis and computer simulations of the passive protection systems against severe accidents and mathematical modelling and simulation of the potentially hazardous objects (PHO) with account of different deviating arguments concerning the real features are considered. It has concern to a need of the planning and decision making in the environmental and other tasks.

  • 4. Kazachkov, I.V
    et al.
    Geraimchuk, M.D
    Fransson, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Development and implementation of multimedia educational systems for universities and secondary schools2007Conference paper (Other academic)
  • 5.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    A combined space discrete algorithm with a taylor series by time for solution of the non-stationary CFD problems2011In: WSEAS Transactions on Fluid Mechanics, ISSN 1790-5087, Vol. 6, no 1, p. 51-69Article in journal (Refereed)
    Abstract [en]

    The first order by time partial differential equation (PDE) is used as models in applications such as fluid flow, heat transfer, solid deformation, electromagnetic waves, and many others. In this paper we propose the new numerical method to solve a class of the initial-boundary value problems for the PDE using any known space discrete numerical schemes and a Taylor series expansion by time. Derivatives by time are got from the outgoing PDE and its further differentiation (for second and higher order derivatives by time). By numerical solution of the PDE and PDE arrays normally a second order discretization by space is applied while a first order by time is sometimes satisfactory too. Nevertheless, in a number of different problems, discretization both by temporal and by spatial variables is needed of highest orders, which complicates the numerical solution, in some cases dramatically. Therefore it is difficult to apply the same numerical methods for the solution of some PDE arrays if their parameters are varying in a wide range so that in some of them different numerical schemes by time fit the best for precise numerical solution. The Taylor series based solution strategy for the non-stationary PDE in CFD simulations has been proposed here that attempts to optimise the computation time and fidelity of the numerical solution. The proposed strategy allows solving the non-stationary PDE with any order of accuracy by time in the frame of one algorithm on a single processor, as well as on a parallel cluster system. A number of examples considered in this paper have shown applicability of the method and its efficiency.

  • 6.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Blow-up regimes by non-isothermal gas/steam filtration through the underground particle layer with internal heat sources2009In: International journal of geology, ISSN 1998-4499, Vol. 3, no 4, p. 101-111Article in journal (Refereed)
    Abstract [en]

    Two-dimensional non-stationary model for the non-isothermal gas/steam filtration through a monospherical particle layer with internal heat generation is considered with a particular emphasis on the non­thermal gas/particles local equilibrium, taking into account the real non-linear properties of the media. The boundary problem for the multiphase system of gas and particles is formulated and solved numerically using the effective finite-difference fractional time-step method. It is shown that some initial thermodynamic perturbations in the system may cause localization of a gas heating (mainly due to a non-linear heat conductivity), which will lead to a temperature escalation in a specific spatial subdomains. Furthermore, the effects of other parameters such as particles’ size and porosity of the layer, an amplitude and a form of an initial temperature perturbation, the level of an initial temperature difference between the gas and solid phases, etc. are analyzed. The model considered can be comparably easily modified for the three-dimensional non-stationary case using the numerical algorithm applied. An examples of computer simulations are presented for the cases of the volcanic geological mains and for the nuclear power safety. The phenomenon of the blow-up regimes due to non-linear heat conductivity causing local abnormal heat escalation in a narrow domain may be of great interest for some natural, as well as technical systems and processes.   

  • 7.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Determination and calculation the critical levels in development of complex systems of different nature with shifted arguments for their investigation and optimal control2017In: WSEAS transactions on systems and control, ISSN 1991-8763, E-ISSN 2224-2856, Vol. 12, p. 21-30Article in journal (Refereed)
    Abstract [en]

    Mathematical modeling and analysis is presented for revealing and investigation of the critical phenomena in a development of complex systems for various natures, the living and the technical ones associated with diverse complicated factors, in particular with a presence of shifted arguments of the system. Intensive research in this direction and developed techniques may optimize the management of the complex systems in financial-economic, natural and other fields. Construction of adequate physical and mathematical models for development of complex systems with shifted arguments, critical modes and their effective control are important tasks for a wide range of contemporary issues. Critical levels in the development of economic, banking, industry, technical, political and other systems necessary to determine and anticipate, to manage their system requirements stable development of the system, without being hit in a critical situation, leading to growing oscillations of system settings.

  • 8.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Heat transfer and dynamics of the droplet on a superheated surface2012In: WSEAS Transactions on Heat and Mass Transfer, ISSN 1790-5044, Vol. 7, no 2, p. 47-57Article in journal (Refereed)
    Abstract [en]

    The conditions governing the collapse of a "Leidenfrost drop", e.g. a liquid drop supported by a vapour film on a heated surface was studied analytically. Robust analytical model for the phenomenon has been developed and numerical simulation has been done. The model was represented by two second-order non-linear differential equations for the radius of evaporating drop and its distance over the heated surface. The results obtained have shown the high-frequent oscillations of the drop over the hot plate until complete evaporation of the drop occurs. In contrast with existing precise complex models, the mathematical model developed was simple and could be used for the qualitative estimation of different parameters and quantitative estimation of the integral behaviours of the drop such as time for complete drop evaporation. The effects of surfactants on the Leidenfrost phenomenon and its industrial applications were discussed.

  • 9.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Parametric Excitation and Suppression of Oscillations at the Interfaces of Continua for the Processes Control: Jet and Film Flows, Granular Media, Flow in a Channel with Phase Change2011In: WSEAS Тransactions on fluid mechanics, ISSN 1790-5087, no 3, p. 1-26Article in journal (Refereed)
    Abstract [en]

    The problem is important for the practical applications in three aspects: 1. Excitation of parameter oscillations in continua in touch with necessity of intensification of various technological and technical processes: heat and mass transfer, mixing, decreasing of viscosity, improving of quality for crystallizating metal and many other phenomena. 2. Excitation of parameter oscillations in touch with nesessity of disintegration of jet and film flows: air spray, spray-coating, metal spraying, dispergation and granulation of materials (e.g. particles’ producing from molten metals), etc. 3. Suppression of parameter oscillations for stabilization of unstable regimes and processes: jet-drop and film screens for protection of diaphragm of experimental thermonuclear reactor, thermal instability and control of fusion reactor, control of electromechanical and electrochemical instabilities, combustion stability, decreasing of hydrodynamic and acoustic resistance, etc. In some cases, parametric control makes possible for not only intensification of processes but also for operation of the processes that are impossible without parametric control.It was considered a lot of different as linear as well as nonlinear model situations. As a result there were obtained some interesting regularities of parametric wave excitation and suppression in film flows including three new phenomena of parametric film decay: resonance decay, soliton-like decay and shock-wave decay. The phenomena were first theoretically predicted and then experimentally invented and investigated. Based on these new phenomena we developed, created and tested the prospective dispergators and granulators for some metals and other materials.  

  • 10.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Stability and stabilization of garnissage on surface in cylindrical channel2019In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 140, p. 442-454Article in journal (Refereed)
    Abstract [en]

    The developed mathematical models of parametric oscillations on the phase change boundaries in a cylindrical channel are presented in a continuation of the previously published paper, which made an introduction to the subject. Analysis of the advanced models and processes described by them, together with the computer simulations, revealed a number of important features of the complex systems with dynamical boundaries of the phase change. Influence of the diverse factors and parameters with their interconnections is investigated in detail: the Peclet number, Bio number, modified Bio number (for the heat flux control system), the ratios of physical properties for the liquid and solid phases, a thickness of a solid layer, and the wave numbers of oscillations. Parameters of a garnissage on the internal surface of a cylindrical channel and the regularities of its instability are discussed for the linear and nonlinear cases. A possibility for the system's stabilization against unstable perturbations is examined using the automatic heat flux control. The control parameters are estimated in computer simulation for a wide range of the variable parameters. The results may be useful for the wall's protection against destruction with the artificially controlled garnissage in the metallurgical machines, as well as in some other applications.

  • 11.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    The mathematical models for penetration of a liquid jets into a pool2011In: WSEAS Тransactions on fluid mechanics, ISSN 1790-5087, p. 1-22Article in journal (Refereed)
    Abstract [en]

    The peculiarities of a jet penetrating the liquid pool of different density were examined by means of the non-linear and linear mathematical models derived including bending instability. Based on experimental observations reported in the literature for a number of situations, the penetration behaviour was assumed to govern the buoyancy-dominated regime. A new analytical solution of the one-dimensional non-linear model was obtained for the jet penetration in this condition, as function of Froude number, jet/ambient fluid density ratio and other parameters. The solution was analysed for a number of limit cases. Analytical solution of the non-linear second-order equation obtained can be of interest for other researchers as the mathematical result.

  • 12.
    Kazachkov, Ivan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Konoval, O. V.
    Non-linear mathematical models for the jets penetrating liquid pool of different density under diverse physical conditions and their simulation2013In: WSEAS Transactions on Applied and Theoretical Mechanics, ISSN 1991-8747, E-ISSN 2224-3429, Vol. 8, no 2, p. 156-169Article in journal (Refereed)
    Abstract [en]

    The problem of modelling and simulation for the jets penetrating pool of other liquids is considered under different physical conditions and situations. It may happen for example in severe accidents at the nuclear power plants in touch with development and operation of the passive protection systems against severe accidents, as well as in many other problems. The specific peculiarities of the penetrating jets are discussed and mathematical modelling of the problem is considered. The non-linear second-order differential equation and the Cauchy problem is analyzed and solved analytically using the simultaneous transformation for both dependent and independent variables. The result obtained may be useful for theoretical and practical applications, where the liquid jet or solid rod is penetrating the pool of other liquid.

  • 13.
    Kazachkov, Ivan
    et al.
    KTH, Superseded Departments, Energy Technology.
    Konovalikhin, M. J.
    Steam flow through the volumetrically heated particle bed2002In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 41, no 11, p. 1077-1087Article in journal (Refereed)
    Abstract [en]

    The paper is devoted to the problem of ex-vessel debris bed coolability, in particular, coolability and quenching of a particulate corium debris bed by water. A number of experiments were performed in the POMECO (POrous MEdia COolability) facility to measure the dry out heat flux in a self-heated bed. A mathematical model for the description of flow of a compressible fluid (steam) through the volumetrically heated porous bed with particular consideration of the non-thermal local equilibrium is formulated and solved numerically using the split step method. It is shown that initial thermodynamic perturbations which, if they grow, will lead to a temperature escalation at a specific location. Furthermore, the data from the RIT (Royal Institute of Technology) POMECO (POrous MEdia COolability) experiments are used for the validation of the model.

  • 14.
    Kazachkov, Ivan
    et al.
    KTH, Superseded Departments, Energy Technology.
    Konovalikhin, M. J.
    Sehgal, B. R.
    Dryout location in a low-porosity volumetrically heated particle bed2001In: Journal of Enhanced Heat Transfer, ISSN 1065-5131, E-ISSN 1563-5074, Vol. 8, no 6, p. 397-409Article in journal (Refereed)
    Abstract [en]

    A mathematical model for the description of flow of a compressible fluid (steam) through the volumetrically heated porous bed with particular consideration of the nonthermal local equilibrium is formulated and solved numerically using the split step method. It is shown that initial thermodynamic perturbations, if they grow, will lead to a temperature escalation at a specific location. Furthermore, the data from the RIT (Royal Institute of Technology) POMECO (porous media coolability) experiments are used for the validation of the model. Experimental investigation of the coolability of heat-generating porous beds, named POMECO, was performed. The subject of this investigation was the dryout heat flux as the limiting parameter for the steady state removal of the generated heat by boiling of the coolant. Focus was placed on low porosity, small particle size, and relatively large scale debris beds. In the debris bed, downcomer(s) of different configurations were built which would channel the water from the water overlayer to the bottom of the bed and develop a two-phase natural circulation flow loop, providing greater mass flow rate in the bed. A database on the enhancement of dryout heat flux by downcomers was obtained for low porosity uniform and stratified beds with heat addition of up to 1 MW/m(3).

  • 15.
    Kazachkov, Ivan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Moghaddam, V. H.
    Specific peculiarities of the jets penetrating the liquid pool of different density under severe accidents at the NPP conditions and their modeling and simulation2012In: WSEAS Transactions on Applied and Theoretical Mechanics, ISSN 1991-8747, E-ISSN 2224-3429, Vol. 7, no 4, p. 276-287Article in journal (Refereed)
    Abstract [en]

    The paper is devoted to one of the problems of the modelling and simulation of the severe accidents at the nuclear power plants (NPP) in touch with development and operation of the passive protection systems against severe accidents. The results of the mathematical modelling and simulation of the jets penetrating the pool of other liquid under diverse conditions as well as an analysis of the experimental data have clearly shown that the falling buoyant jets penetrating the pool of other liquid differ a lot from the classical jets moved by pressure gradient. For example, the classic scheme with monotone jet radius evolution does not work in this case. There is clearly observed phenomenon that jet is going with nearly constant radius up to some point in a pool, then at the point of "bifurcation" it substantially changes its radius abruptly (jet switches its one constant radius to the another one). These specific peculiarities of the penetrating jets are discussed and mathematical modelling of the problem is considered.

  • 16.
    Kazachkov, Ivan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Palm, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Analysis of Annular Two-phase Flow Dynamics under Heat Transfer Conditions2005In: Journal of Enhanced Heat Transfer, ISSN 1065-5131, E-ISSN 1563-5074, Vol. 1, p. 1-22Article in journal (Refereed)
    Abstract [en]

    An analytical investigation was performed for the instability phenomenon of two-phase annular flow with a thin film flow on the channel wall under the heat transfer conditions. The analyses of heat transfer behaviours of two-phase annular flow showed that the overall heat transfer behaviours between the fluids and the channel wall were dominated by the thickness of a thin liquid film. The mass, momentum and energy equations for two phases were employed to study the perturbation behaviours in both fluids. Two different boundary conditions at the wall were considered: heat transfer with constant temperature along the wall and then conditions of constant heat transfer along the wall. Basic equations were solved on both hydrodynamic and thermal perturbations in two fluids for two different boundary conditions. Scrupulous analysis was done for the axially symmetrical wave at two-phase interface. The results showed that in case of small flow rate, the hydrodynamic perturbations in both fluids always decreased. Only kinematical waves at the gas-liquid interface could exist, but did not grow. The waves moved at the same velocity as the gas phase in the channel core. However, the thermal perturbations might grow in some conditions. They finally caused hydrodynamic perturbations, which might also grow, causing a flow instability. The solutions for characteristics of the interface waves such as wavelength and increment of perturbations were obtained. More interestingly, for the isothermal boundary conditions it was found that the maximum increment of perturbations (most unstable) was only dependent on the thermodynamical property ratios of the gas and liquid.

  • 17.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Nizhyn Gogol State University, Ukraine.
    Modeling of stability control in a thin layer of solidifying melt on cylindrical surface2018In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 125, p. 395-404Article in journal (Refereed)
    Abstract [en]

    Parametric oscillations of phase transition boundaries, which, unlike surface oscillations of liquid metal film flows described in literature, are shown as defined by an energy exchange between the electromagnetic regulator and the object. While the force influence was considered in film flows, here we consider the thermal influence that makes the frequency of the applied electromagnetic field irrelevant. It has to be rather high so that Joule heat dissipation could occur in a thin skin-layer near the boundary of phase transition (for implementation of the boundary control). Oscillations of phase transition boundaries reveal a low frequency; the system exhibits considerable inertness in thermodynamic relation. Thus, stabilization (suppression of oscillations) is possible at the expense of Joule heat dissipation, i.e. the stabilizing effect of an electromagnetic field is mediated and force actions, as it was demonstrated by our experiments, are rather small. The problem is of practical interest for protection of the metallurgical aggregate machines against high-temperature and chemically aggressive melt with artificial controlled thin layer of garnissage.

  • 18.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Parametric excitation and suppression of oscillations at the interfaces of continua for the processes’ control in jet and film flows, channel flows with phase change and in granular media2015In: WSEAS Transactions on Applied and Theoretical Mechanics, ISSN 1991-8747, E-ISSN 2224-3429, Vol. 10, p. 1-23Article in journal (Refereed)
    Abstract [en]

    The problem is interesting theoretically and important for the practical applications in three aspects: 1. Excitation of parameters’ oscillations in continua in touch with intensification of various technological and technical processes: heat and mass transfer, mixing, decreasing the viscosity, improving the quality for crystallizing metal and many other phenomena. 2. Excitation of parameters’ oscillations in touch with necessity of disintegration of jet and film flows: air spray, spray-coating, metal spraying, dispersing and granulation of materials (e.g. particles’ producing from molten metals), etc. 3. Suppression of oscillations for stabilization of unstable regimes and processes: jet-drop and film screens for protection of diaphragm of experimental thermonuclear reactor, thermal instability and fusion control in reactor, control of electromechanical and electrochemical instabilities, combustion stability, decreasing the hydrodynamic and acoustic resistance, etc. In some cases, parametric control makes possible not just intensification the processes but also running such processes, which are impossible without parametric control. A lot of different linear as well as nonlinear model situations have been considered. As a result some interesting peculiarities of parametric wave excitation and suppression in film flows including three new phenomena of parametric film decay were revealed: resonant decay, soliton-like decay and shock-wave decay. The phenomena were first theoretically predicted and then experimentally invented and investigated. Based on these new phenomena we developed, created and tested the prospective dispersion and granulation machines for some metals and other materials.

  • 19. Moghaddam, V. H.
    et al.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. National Technical University of Ukraine.
    About modeling of the corium jet penetrating the pool of volatile coolant under reactor vessel2010In: Applied computer science, 2010, p. 89-95Conference paper (Refereed)
    Abstract [en]

    The mathematical model developed and some results of its application to an element of a passive protection system against severe accidents at the nuclear power plant (NPP) with a water pool under reactor vessel for corium melt and particles' cooling are presented in the paper. This is an important element of a passive protection system against severe accidents at NPP, which must keep nuclear fuel and other radioactive materials (corium) inside the containment. The penetration behavior of a high-temperature corium jet into a pool of volatile coolant (water), with account of the vapor produced on a melt jet penetration, has been investigated. Success of the problem's solution determines an effectiveness and durability of the passive protection system against severe accidents. Therefore the results obtained may be useful for the development and calculation of such passive protection systems at the NPP. Except theoretical interest for the dynamics of multiphase flows, the problem is of interest for practical applications in nuclear power safety problems, which are probably the most important in further development of the nuclear power industry in the world. Present operation of the nuclear power plants (NPP) still considered by many countries as the highest priority energy source requires strict nuclear power safety substantiation. In the nuclear reactors of the third generation, which are necessary at the change to the operable reactors of the second generation, the passive systems (they are capable for work even under the conditions of the complete NPP de-energizing) must work perfect under any severe accident scenario, to localize emergency and prevent spreading of the radioactive fuel outside the containment.

  • 20. Moghaddam, V. H.
    et al.
    Kazachkov, Ivan V.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Multimedia adaptive interactive teaching-learning environment for energy technology2010In: Recent Advances In Circuits, Systems And Signals, World Scientific and Engineering Academy and Society, 2010, p. 64-69Conference paper (Refereed)
    Abstract [en]

    The computerized educational (CompEdu) platform is based on the multimedia interactive presentation of a slide show of lecturing material in a non-conventional way where instead of classical linear presentations of the important information, the material is presented in a progressive and concise way ensuring the coverage of large portions of material in shortest number of pages. In this paper, some recent results in the development and implementation of the virtual university environment are presented and discussed. Also some prospectives and advantages of this form of teaching-learning, as well as some questions of international collaboration in the field are discussed too.

  • 21.
    Tomyak, Roman
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Fransson, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Case study tool as interactive learning material in computerized educational system2010Conference paper (Other academic)
  • 22.
    Tomyak, Roman
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Kazachkov, Ivan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Fransson, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Case study tools in the multimedia interactive teaching-learning platform for energy technology2010In: Applied computer science, 9789604742257, 2010, p. 156-162Conference paper (Refereed)
    Abstract [en]

    The tools called case study are normally presented in the computerized educational (CompEdu) platform as short pages with popups giving precise short introduction into some narrow subject. The CompEdu is based on the multimedia interactive presentation of a slide show of lecturing material in a non-conventional way where the material is presented in a progressive and concise way ensuring the coverage of large portions of material in shortest number of pages. In this paper, some recent results in the development of case studies by different subjects with emphasize of the new combustion systems are presented and discussed. Also some methodological aspects and features are discussed concerning their advantages for intensive and easy (pleasant) form of teaching-learning using computerized system developed at EGI/KTH.

  • 23. Yang, Z. L.
    et al.
    Kazachkov, Ivan
    KTH, Superseded Departments, Energy Technology.
    Palm, Björn E.
    KTH, Superseded Departments, Energy Technology.
    An analytical model on the instability of thin film flow dynamics in a micro-gap channel2001In: Journal of Enhanced Heat Transfer, ISSN 1065-5131, E-ISSN 1563-5074, Vol. 8, no 3, p. 175-184Article in journal (Refereed)
    Abstract [en]

    In this paper, a mathematical model is developed to investigate the liquid film dynamics in micro-gap channels, in which a liquid film flows along the wall surfaces and gas flows in the channel core. It is assumed that the Reynolds numbers for both gas and liquid flow are very low and there is no mass transfer at the interface. The instability behavior of the interface of two-phase flow is analysed by employing Stoke's equations, which are solved by non-linear boundary conditions. The solution shows that if the perturbations at the interface are small, they do not grow, however, kinematic waves still exist. All perturbations on the film surface are convoyed by gas flow without growing or decreasing. From the analytical results it is also found that in a micro-gap-channel in the case of constant pressure gradient, the perturbations on both sides of the gap interface are strictly interconnected, and their relationship has been obtained.

1 - 23 of 23
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Output format
  • html
  • text
  • asciidoc
  • rtf