2008 Second International Conference on Thermal Issues in Emerging Technologies最新文献

Nonlinear thermal resistance control equations for adaptive multiple cooling surface CTM, and boundary condition independent multiple heatsources CTM 自适应多冷却面CTM的非线性热阻控制方程，以及独立于多热源CTM的边界条件

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167166

P. Tounsi, F. Madrid, J. Nowakowski

引用次数: 0

Cooling of CPU with a thermosyphon 用热虹吸冷却中央处理器

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167184

R. Khodabandeh, M. Lindstrom

引用次数: 2

Air flow regimes and IAQ modeling in air conditioned spaces 空调空间的气流状态和室内空气质量模型

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167197

E. Khalil

引用次数: 1

Experimental study on cooling air flow in a thin electronics casing model 电子薄型机壳模型冷却气流的实验研究

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167168

M. Ishizuka, S. Nakagawa, Y. Nishino, T. Fukue

引用次数: 1

Slot jet impingement heat transfer from an isothermal circular cylinder 等温圆柱槽射流冲击传热

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167189

M. Ashjaee, S. Amiri, K. Habibi

{"title":"Slot jet impingement heat transfer from an isothermal circular cylinder","authors":"M. Ashjaee, S. Amiri, K. Habibi","doi":"10.1109/THETA.2008.5167189","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167189","url":null,"abstract":"The heat transfer characteristics of a circular cylinder exposed to a slot jet impingement of air has been studied experimentally. The study focused on low Reynolds numbers ranging from 120 to 1210 and slot-to-cylinder spacing from 2 to 8 of the slot width. A Mach-Zehnder interferometer was used in the experimental study. Local Nusselt numbers at cylinder surface were obtained using infinite fringe mode which corresponds directly to isotherms in the flow field. It has shown that the local Nusselt number has a maximum value at the stagnation point and then decreases to a minimum distance between isotherms. It is observed that slot jet impingement has a great effect on the local heat transfer coefficient from the stagnation point to the angle of 120deg and local Nusselt number at the downstream is approximately similar to the case of free convection for the low and moderate Reynolds numbers. In addition, increasing the distance between nozzle and cylinder decreases average heat transfer coefficients. In order to check the accuracy of the experiment and method of data reduction first the case of free convection was tested and the results were compared with the previous works which has an excellent agreement.","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":"134218400","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}

引用次数: 8

Convective heat transfer in graphite foams with complex structures 复杂结构石墨泡沫的对流换热

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167192

K. Leong, Hongying Li, Liwen Jin, J. Chai

{"title":"Convective heat transfer in graphite foams with complex structures","authors":"K. Leong, Hongying Li, Liwen Jin, J. Chai","doi":"10.1109/THETA.2008.5167192","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167192","url":null,"abstract":"Along with recent advances in electronic packaging, high performance computer processors require more efficient devices for dissipating the high heat fluxes. The use of highly conductive porous media has emerged as an effective cooling method due to its large internal contact surface area which enhances convection at the pore level. In this study, graphite foams developed at Oak Ridge National Laboratory, USA, are used to enhance heat transfer. Initial studies performed by other investigators showed that the extended surface area also results in very high pressure drop for fluid flowing through the graphite foam. This paper presents a numerical and experimental study of convection heat transfer in graphite foams with different structures which are designed to reduce pressure drop. The non local thermal equilibrium model is adopted in the fluid and solid energy equations. The numerical results which are validated by experimental data show that the inlet air flow partially penetrates the designed foam walls and the rest of the air flows tortuously through slots in the structure. Flow mixing is observed in the free stream area inside the structures, which is absent in block graphite foam. This indicates that better convection can be obtained by these structures due to their low flow resistance and high flow velocity. The pressure drop in the designed graphite foam is also found to be significantly lower than that in solid block graphite foam.","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":"116988058","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}

引用次数: 2

Improvement of room temperature magnetic refrigerator using air as heat transfer fluid 以空气为传热流体的室温磁制冷机的改进

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167187

K. Nakamura, T. Kawanami, S. Hirano, M. Ikegawa, K. Fumoto

{"title":"Improvement of room temperature magnetic refrigerator using air as heat transfer fluid","authors":"K. Nakamura, T. Kawanami, S. Hirano, M. Ikegawa, K. Fumoto","doi":"10.1109/THETA.2008.5167187","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167187","url":null,"abstract":"In order to elucidate the cooling characteristics and to improve the cooling performance of a room temperature magnetic refrigerator using air as a heat transfer fluid, experimental and analytical study concerned with the heat transfer characteristics of an active magnetic regenerator (AMR) are conducted. The basic components of the target system are a magnetic circuit, a test section, a fluid supplying system and an associated instrumentation. Spherical gadolinium particles are packed in the test section as a magnetic working substance. Temperature profiles under several operating conditions for the Air-AMR are measured and calculated. Also, those for the Water-AMR are investigated in order to compare with the Air-AMR. The results show that the AMR cycle is very effective for improvement of the cooling performance of a room-temperature magnetic refrigerator for both heat transfer fluids, because increase in the temperature span between the hot-end and the cold-end due to regeneration is realized. Furthermore, it is revealed that a high flow rate of air is necessary in order to improve the cooling performance of the Air-AMR refrigerator, compared with the case of the Water-AMR. It is also shown that thermophysical properties of the heat transfer fluid have a significant effect on the cooling characteristics of an AMR refrigerator.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"153 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":"116419325","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}

引用次数: 11

Heat transfer performance of Aluminum foams during single phase air flow 泡沫铝在单相气流中的传热性能

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167190

A. Cavallini, S. Mancin, L. Rossetto, C. Zilio

引用次数: 3

Boiling in macro and micro systems: Existing problems and ways of further research 宏观和微观系统中的沸腾:存在的问题和进一步研究的途径

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167183

I. Shekriladze

{"title":"Boiling in macro and micro systems: Existing problems and ways of further research","authors":"I. Shekriladze","doi":"10.1109/THETA.2008.5167183","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167183","url":null,"abstract":"A keynote paper presents just the next attempt to promote a discussion of modern state of art in the field of boiling heat transfer research. It is shown how unwillingness to deconstruct internal contradictions of applicable approaches has resulted longstanding theoretical deadlock. Alternatively, it also is shown how resolution of these contradictions opens the ways to breakthrough in boiling heat transfer theory Principal contradictions between experimental knowledge and traditional model of ldquothe theatre of actorsrdquo (MTA) are discussed. Basic experimental facts, physical models and correlations of experimental data are reconsidered. Crucial role of pumping effect of growing bubble (PEGB) in boiling heat transfer and hydrodynamics is shown. Basic role of control of HTC by thermodynamic conditions on nucleation sites is demonstrated and consequent model of ldquothe theatre of directorrdquo (MTD) is discussed. Universal MTD-based correlation of boiling HTC of all types of liquids is considered. Unified consistent research framework for developed boiling heat transfer and diverse specific boiling heat transfer regimes is outlined through supplementing MTD by so-called multifactoring concept (MFC). MFC links transition from developed boiling mode to diverse boiling curves to a phenomenon of multiplication of factors influencing HTC. It is shown also that multifactoring phenomenon equally can cover any boiling process including boiling in minichannels and microchannels. Possible types of multifactoring are considered. The ways of further research of the boiling problem are discussed.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"27 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":"126747289","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}

引用次数: 0

Integrating a thermo-mechanical solver into the DJOSER analytical thermal simulator for multilayer power electronic assemblies. Preliminary results 将热机械求解器集成到DJOSER多层电力电子组件分析热模拟器中。初步结果

2008 Second International Conference on Thermal Issues in Emerging Technologies Pub Date : 2008-12-01 DOI: 10.1109/THETA.2008.5167180

P. Bagnoli, C. Padovani, A. Pagni, G. Pasquinelli

{"title":"Integrating a thermo-mechanical solver into the DJOSER analytical thermal simulator for multilayer power electronic assemblies. Preliminary results","authors":"P. Bagnoli, C. Padovani, A. Pagni, G. Pasquinelli","doi":"10.1109/THETA.2008.5167180","DOIUrl":"https://doi.org/10.1109/THETA.2008.5167180","url":null,"abstract":"The DJOSER analytical thermal solver for multilayer mounting structures has been tested as a useful and friendly tool for the thermal analysis of power electronic devices and their packages, able to replace the onerous programs based on the finite element (FEM) calculations. The other problem connected with the packaging evaluation is the calculation of the thermally induced stresses and strains in the various layers composing the assembling structures. This paper deals with the first step of the implementation of a thermo-mechanical solver to be connected with the DJOSER program, which may be able to calculate the stresses at the layer interfaces, using the same strategy, i.e. a semi-analytical mathematical approach, and the same DJOSER structural constrains (stepped pyramidal structures, homogeneous layers). The basic theory is briefly exposed and the method is applied to some two-layers virtual structures. The obtained results are compared with those obtained using standard FEM analyses, revealing a substantial agreement but also some local disagreements.","PeriodicalId":414963,"journal":{"name":"2008 Second International Conference on Thermal Issues in Emerging Technologies","volume":"18 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":"134525813","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}

引用次数: 1