Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167194
E. Khalil
The Egyptian community in its path for rapid development is endeavouring to make all necessary and appropriate measures to enhance the efficiency of energy utilization and increase the beneficiation of the energy resources. The energy production, transmission, distribution and utilization efficiency becomes a vital factor and measure of national development. The different governmental organisation was established earlier to be responsible for energy planning and efficient utilization, information dissemination and capacity building. Throughout the Nation Energy resources are widely used and consumption rates are in general exceeding the International accepted values. The use and application of new and renewable energy sources can be harnessed to design, construct and operate a solar building of moderate size for desert applications.
{"title":"Efficient energy utilization in air conditioned buildings in Egypt: New directive","authors":"E. Khalil","doi":"10.1109/THETA.2008.5167194","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167194","url":null,"abstract":"The Egyptian community in its path for rapid development is endeavouring to make all necessary and appropriate measures to enhance the efficiency of energy utilization and increase the beneficiation of the energy resources. The energy production, transmission, distribution and utilization efficiency becomes a vital factor and measure of national development. The different governmental organisation was established earlier to be responsible for energy planning and efficient utilization, information dissemination and capacity building. Throughout the Nation Energy resources are widely used and consumption rates are in general exceeding the International accepted values. The use and application of new and renewable energy sources can be harnessed to design, construct and operate a solar building of moderate size for desert applications.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126242129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167159
P. Agostinetti, M. Boldrin, F. Fantini
The Neutral Beam Injectors (NBIs) of the ITER experimental fusion reactor are designed to accelerate Deuterium negative ions with energy up to 1 MeV and current up to 40 A. The accelerator grids must be designed to operate at high voltages and to withstand high power densities (in the order of some tens of MW m-2). They must maintain a proper alignment in all the foreseen operating scenarios, in order to obtain good beam optics, so the thermo-mechanical deformations must be maintained at very low values. Further requirements come from the need of keeping under control the maximum surface temperature in copper. With these requirements, the cooling of the grids represents a significantly critical aspect of the NBI design. Coolant properties have to satisfy high resistivity requirements and to be appropriate for the removal of high heat loads. The cooling circuits must match with the beam optic geometry and the space constrains severely affect the coolant distribution. This paper presents some studies of the grid cooling circuits design carried out with Computational Fluid Dynamics (CFD) numerical simulations and analytical methods. Cooling performances for different cooling fluids (water and dielectric coolants) have been investigated.
{"title":"Evaluation of different colling fluids for high-voltage Neutral Beam Injector grids","authors":"P. Agostinetti, M. Boldrin, F. Fantini","doi":"10.1109/THETA.2008.5167159","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167159","url":null,"abstract":"The Neutral Beam Injectors (NBIs) of the ITER experimental fusion reactor are designed to accelerate Deuterium negative ions with energy up to 1 MeV and current up to 40 A. The accelerator grids must be designed to operate at high voltages and to withstand high power densities (in the order of some tens of MW m-2). They must maintain a proper alignment in all the foreseen operating scenarios, in order to obtain good beam optics, so the thermo-mechanical deformations must be maintained at very low values. Further requirements come from the need of keeping under control the maximum surface temperature in copper. With these requirements, the cooling of the grids represents a significantly critical aspect of the NBI design. Coolant properties have to satisfy high resistivity requirements and to be appropriate for the removal of high heat loads. The cooling circuits must match with the beam optic geometry and the space constrains severely affect the coolant distribution. This paper presents some studies of the grid cooling circuits design carried out with Computational Fluid Dynamics (CFD) numerical simulations and analytical methods. Cooling performances for different cooling fluids (water and dielectric coolants) have been investigated.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133619269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1615/ICHMT.2008.CHT.1940
J. Mansouri, S. Maalej, M. Zaghdoudi
A detailed mathematical model of a two-phase heat spreader with axial microchannels is developed in which the fluid flow is considered along with the heat and mass transfer processes during evaporation and condensation. The model is based on the equations for the mass, momentum and energy conservation, which are written for the evaporator, adiabatic, and condenser zones. The model, which permits to simulate several shapes of microchannels, can predict the maximum heat transfer capacity of the two-phase heat spreader, the optimal fluid mass, and the temperatures and pressure gradients along the microchannel. The effect of shear stresses at the free liquid surface in a microchannel due to the frictional liquid-vapor interaction on the liquid flow is taken into consideration. The heat transfer through the liquid films in both evaporator and condenser is accounted for in the model, which is described with respect to the disjoining pressure, interfacial thermal resistance, surface roughness, and curvature. The thermal resistances of the evaporator and condenser are determined by accounting for the longitudinal distribution of the meniscus curvature, which is dependent on heat load and heat spreader inclination.
{"title":"Theoretical investigation on the thermal prformance of flat two-phase heat spreaders with microchannels","authors":"J. Mansouri, S. Maalej, M. Zaghdoudi","doi":"10.1615/ICHMT.2008.CHT.1940","DOIUrl":"https://doi.org/10.1615/ICHMT.2008.CHT.1940","url":null,"abstract":"A detailed mathematical model of a two-phase heat spreader with axial microchannels is developed in which the fluid flow is considered along with the heat and mass transfer processes during evaporation and condensation. The model is based on the equations for the mass, momentum and energy conservation, which are written for the evaporator, adiabatic, and condenser zones. The model, which permits to simulate several shapes of microchannels, can predict the maximum heat transfer capacity of the two-phase heat spreader, the optimal fluid mass, and the temperatures and pressure gradients along the microchannel. The effect of shear stresses at the free liquid surface in a microchannel due to the frictional liquid-vapor interaction on the liquid flow is taken into consideration. The heat transfer through the liquid films in both evaporator and condenser is accounted for in the model, which is described with respect to the disjoining pressure, interfacial thermal resistance, surface roughness, and curvature. The thermal resistances of the evaporator and condenser are determined by accounting for the longitudinal distribution of the meniscus curvature, which is dependent on heat load and heat spreader inclination.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130801241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167162
S. Cordiner, A. Mariani, V. Mulone
The development of kW-size stacks of Solid Oxide Fuel Cells (SOFCs) requires the solution of many and different technological issues to improve reliability and reduce costs. The use of micro-tubular technology may help to solve some of these issues, especially by utilizing a modular approach to build the largest as possible "repeatable units". However, reactant flows and geometries must be carefully designed to get a good behavior in terms of power output and homogeneity of exploitation of all the electrochemical material. An integrated CFD approach based on multi-dimensional analysis to design modular micro-tubular SOFCs is proposed in this paper. It is composed by two distinct tools (namely detailed and fast): they are characterized by different accuracy and computational expenses. The whole model is first validated with a specifically implemented experiment of a single channel SOFC. Then, it is applied to analyze the coupling among heat transfer, fluid-dynamics and electrochemistry of increasingly complex systems (micro and midi-reactors, constituting respectively 15 and 45 tube assemblies). Finally, it is utilized to optimize the geometry of the cited modular systems in terms of air and heat release management to get the maximum performance in terms of power density keeping as low as possible the impact of thermal stresses on cell durability.
{"title":"An integrated CFD-approch to deisgn micro-tubular Solid Oxide Fuel Cells","authors":"S. Cordiner, A. Mariani, V. Mulone","doi":"10.1109/THETA.2008.5167162","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167162","url":null,"abstract":"The development of kW-size stacks of Solid Oxide Fuel Cells (SOFCs) requires the solution of many and different technological issues to improve reliability and reduce costs. The use of micro-tubular technology may help to solve some of these issues, especially by utilizing a modular approach to build the largest as possible \"repeatable units\". However, reactant flows and geometries must be carefully designed to get a good behavior in terms of power output and homogeneity of exploitation of all the electrochemical material. An integrated CFD approach based on multi-dimensional analysis to design modular micro-tubular SOFCs is proposed in this paper. It is composed by two distinct tools (namely detailed and fast): they are characterized by different accuracy and computational expenses. The whole model is first validated with a specifically implemented experiment of a single channel SOFC. Then, it is applied to analyze the coupling among heat transfer, fluid-dynamics and electrochemistry of increasingly complex systems (micro and midi-reactors, constituting respectively 15 and 45 tube assemblies). Finally, it is utilized to optimize the geometry of the cited modular systems in terms of air and heat release management to get the maximum performance in terms of power density keeping as low as possible the impact of thermal stresses on cell durability.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128737411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5188777
S. Mohamed-Nabil, S. Ossama
The convection heat transfer coefficient h is a concept that is heavily used by all thermal engineers to solve practical problems. It allows them to approximately analyze complicated systems, without having to systematically perform detailed 3D simulations of all parts of any real system, which is always highly complicated. At least in the first design phase, engineers would appreciate a `handy¿ approximation, like that of h, which belongs to a larger category of what is called compact models. However, defining and using this quantity h for system simulation suffers from fundamental and conceptual problems that will be elucidated in this paper. Experienced thermal engineers know how to use it judiciously avoiding thus these problems, almost unconsciously. However as systems become more and more complicated, in terms of the number of its elements, automated calculations are becoming the rule. Hence, a `black box¿ model of convection is needed for system level simulation and design, which would always give meaningful results in any situation. In this paper a solution is proposed based on the general theory of compact models, which has known recent breakthroughs leading to a general and rigorous theory. This theory has been applied so far for thermal modeling of conduction problems. It will be generalized here to convection problems. The result is a new concept that generalizes h such as to be able to correctly handle situations that were not adequately modeled before.
{"title":"Generalization of the heat transfer coefficient concept","authors":"S. Mohamed-Nabil, S. Ossama","doi":"10.1109/THETA.2008.5188777","DOIUrl":"https://doi.org/10.1109/THETA.2008.5188777","url":null,"abstract":"The convection heat transfer coefficient h is a concept that is heavily used by all thermal engineers to solve practical problems. It allows them to approximately analyze complicated systems, without having to systematically perform detailed 3D simulations of all parts of any real system, which is always highly complicated. At least in the first design phase, engineers would appreciate a `handy¿ approximation, like that of h, which belongs to a larger category of what is called compact models. However, defining and using this quantity h for system simulation suffers from fundamental and conceptual problems that will be elucidated in this paper. Experienced thermal engineers know how to use it judiciously avoiding thus these problems, almost unconsciously. However as systems become more and more complicated, in terms of the number of its elements, automated calculations are becoming the rule. Hence, a `black box¿ model of convection is needed for system level simulation and design, which would always give meaningful results in any situation. In this paper a solution is proposed based on the general theory of compact models, which has known recent breakthroughs leading to a general and rigorous theory. This theory has been applied so far for thermal modeling of conduction problems. It will be generalized here to convection problems. The result is a new concept that generalizes h such as to be able to correctly handle situations that were not adequately modeled before.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130544050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167195
G. Baldinelli, F. Asdrubali
The paper deals with the analytical evaluation of energy advantages that could be obtained by inserting a panel made of reflecting material between the wall and radiators used for central heating. As a consequence of the panel installation, a higher percentage of the heat emitted by the radiator remains inside the room to be warmed, diminishing the heat loss through the external wall, thus improving the global efficiency of the entire heating system. The analysis is based on equations that describe the heat exchange by irradiation between the three surfaces: radiator, reflecting panel and inner surface of the external wall; the natural convection with interior room air flow is also taken into account. The study covers three different wall types, with the aim of investigating the influence of the enclosure on the panel performance, and three different climatic zones in Italy (North, Centre and South), to take into account the variation with the external temperature. Results show how the performance of the reflecting panel depends strictly on the insulation level of the external wall facing the radiator; more specifically, efficiency increases when the thermal resistance decreases, reaching energy savings of up to 8.8% in worst insulation conditions. The variability with external temperature conditions is negligible, showing similar values for all the investigated zones.
{"title":"Reflecting panels for radiators in residential buildings: Theoretical analysis of energy performance","authors":"G. Baldinelli, F. Asdrubali","doi":"10.1109/THETA.2008.5167195","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167195","url":null,"abstract":"The paper deals with the analytical evaluation of energy advantages that could be obtained by inserting a panel made of reflecting material between the wall and radiators used for central heating. As a consequence of the panel installation, a higher percentage of the heat emitted by the radiator remains inside the room to be warmed, diminishing the heat loss through the external wall, thus improving the global efficiency of the entire heating system. The analysis is based on equations that describe the heat exchange by irradiation between the three surfaces: radiator, reflecting panel and inner surface of the external wall; the natural convection with interior room air flow is also taken into account. The study covers three different wall types, with the aim of investigating the influence of the enclosure on the panel performance, and three different climatic zones in Italy (North, Centre and South), to take into account the variation with the external temperature. Results show how the performance of the reflecting panel depends strictly on the insulation level of the external wall facing the radiator; more specifically, efficiency increases when the thermal resistance decreases, reaching energy savings of up to 8.8% in worst insulation conditions. The variability with external temperature conditions is negligible, showing similar values for all the investigated zones.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"52 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132442777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Satake, G. Sorimachi, T. Kanai, J. Taniguchi, N. Unno
High time-resolution flow field measurement in the glass plate with covered glass with two holes is performed by micro-DHPTV system. The glass plate with covered glass has two holes that are inside photo-curable resin. The particle measurement is performed during two seconds; the measurement time is covered for curing time. The theoretically curing time is estimated from the irradiation flux of UV source. Moreover, photo-curable resin with changing of temperature is measured to evaluate dependence of temperature. Consequently, the seeding particle tracking can be obtained instantaneously. The three-dimensional displacement from the tracking is mainly caused at the depth direction. The value is in good agreement with the theoretical displacement from UV irradiation flux. Moreover, it is found that the photo curing of the displacement appears to be proportional to increasing the temperature.
{"title":"Three-dimensional measurements of photo curing with process with photo-curable resin for UV-nanoimprint by micro-digital-holographic-PTV","authors":"S. Satake, G. Sorimachi, T. Kanai, J. Taniguchi, N. Unno","doi":"10.1115/1.4001854","DOIUrl":"https://doi.org/10.1115/1.4001854","url":null,"abstract":"High time-resolution flow field measurement in the glass plate with covered glass with two holes is performed by micro-DHPTV system. The glass plate with covered glass has two holes that are inside photo-curable resin. The particle measurement is performed during two seconds; the measurement time is covered for curing time. The theoretically curing time is estimated from the irradiation flux of UV source. Moreover, photo-curable resin with changing of temperature is measured to evaluate dependence of temperature. Consequently, the seeding particle tracking can be obtained instantaneously. The three-dimensional displacement from the tracking is mainly caused at the depth direction. The value is in good agreement with the theoretical displacement from UV irradiation flux. Moreover, it is found that the photo curing of the displacement appears to be proportional to increasing the temperature.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129458791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167191
Z. Alloui, H. Beji, P. Vasseur
This paper reports an analytical and numerical study of natural convection in a horizontal binary fluid layer confined between two horizontal porous walls. The cavity is heated from the bottom by a constant heat flux while the long side walls are impermeable and adiabatic. The Beavers-Joseph slip condition on velocity is applied at the interface between the fluid and porous layers. Both double-diffusive convection and Soret-induced convection are considered. An analytical model, based on the parallel flow approximation, is proposed for the case of a shallow layer. The flow and heat and mass transfer variables are obtained in terms of the governing parameters of the problem. The critical Rayleigh numbers for the onset of supercritical and subcritical convection are predicted for various hydrodynamic boundary conditions. The results for a fluid layer bounded by solid walls and free surfaces emerge from the present analysis as limiting cases. The study is completed by a numerical solution of the full governing equations.
{"title":"Natural convection in a horizontal fluid layer bounded by thin porous boundaries","authors":"Z. Alloui, H. Beji, P. Vasseur","doi":"10.1109/THETA.2008.5167191","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167191","url":null,"abstract":"This paper reports an analytical and numerical study of natural convection in a horizontal binary fluid layer confined between two horizontal porous walls. The cavity is heated from the bottom by a constant heat flux while the long side walls are impermeable and adiabatic. The Beavers-Joseph slip condition on velocity is applied at the interface between the fluid and porous layers. Both double-diffusive convection and Soret-induced convection are considered. An analytical model, based on the parallel flow approximation, is proposed for the case of a shallow layer. The flow and heat and mass transfer variables are obtained in terms of the governing parameters of the problem. The critical Rayleigh numbers for the onset of supercritical and subcritical convection are predicted for various hydrodynamic boundary conditions. The results for a fluid layer bounded by solid walls and free surfaces emerge from the present analysis as limiting cases. The study is completed by a numerical solution of the full governing equations.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116339543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167178
P. OisínF., Lyons, Tim, Persoons, Gerard, Byrne, B. Darina, Murray
Mist jets, which involve the addition of a fine water mist to an air flow, have the potential to improve on the heat transfer performance of impinging air jets. Much is already known about the heat transfer characteristics of impinging air jets, and they are widely used in many engineering applications. This project seeks to improve the understanding of mist jets and provide heat transfer correlations and identify the heat transfer mechanism involved. To date a fully functional test rig has been built and calibrations and initial tests carried out. Comparison of the heat transfer characteristics of these mist jets with previous literature on both air and mist jets is underway.
{"title":"Water mist / air jet cooling of a heated plate with variable droplet size","authors":"P. OisínF., Lyons, Tim, Persoons, Gerard, Byrne, B. Darina, Murray","doi":"10.1109/THETA.2008.5167178","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167178","url":null,"abstract":"Mist jets, which involve the addition of a fine water mist to an air flow, have the potential to improve on the heat transfer performance of impinging air jets. Much is already known about the heat transfer characteristics of impinging air jets, and they are widely used in many engineering applications. This project seeks to improve the understanding of mist jets and provide heat transfer correlations and identify the heat transfer mechanism involved. To date a fully functional test rig has been built and calibrations and initial tests carried out. Comparison of the heat transfer characteristics of these mist jets with previous literature on both air and mist jets is underway.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122681558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-12-01DOI: 10.1109/THETA.2008.5167167
H. Shokouhmand, M. Goharkhah, S. Amiri
In this paper, the non-Fourier heat conduction problem in a finite slab is analyzed. Dependence of thermal conductivity on space which is mostly encountered in nonhomogeneous materials has been considered. HHC equation has been solved by employing trial solution method and collocation optimization criterion. A temperature peak on the insulated wall of the slab has been observed due to linear variation of thermal conductivity, so the main feature of this article is to find the amount of temperature peak and the time at which it occurs. It has been shown that the magnitude of the temperature peak increases with increasing the dimensionless relaxation time. In order to validate the approach, the results have been compared with the analytical solution obtained for a special case which shows a good agreement.
{"title":"Analytical solution of hyperbolic heat conduction equation in a thin film layer with space-dependent thermal conductivity","authors":"H. Shokouhmand, M. Goharkhah, S. Amiri","doi":"10.1109/THETA.2008.5167167","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167167","url":null,"abstract":"In this paper, the non-Fourier heat conduction problem in a finite slab is analyzed. Dependence of thermal conductivity on space which is mostly encountered in nonhomogeneous materials has been considered. HHC equation has been solved by employing trial solution method and collocation optimization criterion. A temperature peak on the insulated wall of the slab has been observed due to linear variation of thermal conductivity, so the main feature of this article is to find the amount of temperature peak and the time at which it occurs. It has been shown that the magnitude of the temperature peak increases with increasing the dimensionless relaxation time. In order to validate the approach, the results have been compared with the analytical solution obtained for a special case which shows a good agreement.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"140 21","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131746058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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