Heat Transfer: Volume 4最新文献_第6页

Pool Boiling Heat Transfer From Plain and Microporous, Square Pin Finned Surfaces in Saturated FC-72 饱和FC-72中平孔和微孔、方销翅片表面的池沸腾传热

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/1.1288708

K. Rainey, S. M. You

{"title":"Pool Boiling Heat Transfer From Plain and Microporous, Square Pin Finned Surfaces in Saturated FC-72","authors":"K. Rainey, S. M. You","doi":"10.1115/1.1288708","DOIUrl":"https://doi.org/10.1115/1.1288708","url":null,"abstract":"\u0000 The present research is an experimental study of “double enhancement” behavior in pool boiling from heater surfaces simulating microelectronic devices immersed in saturated FC-72 at atmospheric pressure. The term “double enhancement” refers to the combination of two different enhancement techniques: a large-scale area enhancement (square pin fin array) and a small-scale surface enhancement (microporous coating). Fin lengths were varied from 0 (flat surface) to 8 mm. Effects of this double enhancement technique on critical heat flux (CHF) and nucleate boiling heat transfer in the horizontal orientation (fins are vertical) are investigated. Results showed significant increases in nucleate boiling heat transfer coefficients with the application of the microporous coating to the heater surfaces. CHF was found to be relatively insensitive to surface microstructure for the finned surfaces except in the case of the surface with 8 mm long fins. The nucleate boiling and CHF behavior has been found to be the result of multiple, counteracting mechanisms: surface area enhancement, fin efficiency, surface microstructure (active nucleation site density), vapor bubble departure resistance, and re-wetting liquid flow resistance.","PeriodicalId":120929,"journal":{"name":"Heat Transfer: Volume 4","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134116013","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: 203

Instability of Flame Spread in Microgravity 微重力下火焰传播的不稳定性

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1118

L. Oravecz, I. Wichman, S. Olson

引用次数: 3

A Tomographic Reconstruction Method for Three-Dimensional Liquid Crystal Thermography 三维液晶热成像的层析重建方法

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1100

D. Mishra, P. M. Lutjen, V. Prasad

引用次数: 0

A New Experimental Technique for Measuring Surface Heat Transfer Coefficients Using Uncalibrated Liquid Crystals 一种利用未校准液晶测量表面传热系数的新实验技术

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1111

W. Turnbull, P. Oosthuizen

{"title":"A New Experimental Technique for Measuring Surface Heat Transfer Coefficients Using Uncalibrated Liquid Crystals","authors":"W. Turnbull, P. Oosthuizen","doi":"10.1115/imece1999-1111","DOIUrl":"https://doi.org/10.1115/imece1999-1111","url":null,"abstract":"\u0000 A new experimental technique has been developed that permits the determination of local surface heat transfer coefficients on surfaces without requirement for calibration of the temperature-sensing device. The technique uses the phase delay that develops between the surface temperature response and an imposed periodic surface heat flux. This phase delay is dependent upon the thermophysical properties of the model, the heat flux driving frequency and the local heat transfer coefficient. It is not a function of magnitude of the local heat flux. Since only phase differences are being measured there is no requirement to calibrate the temperature sensor, in this instance a thermochromic liquid crystal. Application of a periodic surface heat flux to a flat plate resulted in a surface colour response that was a function of time. This response was captured using a standard colour CCD camera and the phase delay angles were determined using Fourier analysis. Only the 8 bit G component of the captured RGB signal was required, there being no need to determine a Hue value. From these experimentally obtained phase delay angles it was possible to determine heat transfer coefficients that compared well with those predicted using a standard correlation.","PeriodicalId":120929,"journal":{"name":"Heat Transfer: Volume 4","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124827349","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

Cooperative Learning in an Introductory Heat Transfer Class 热传递入门课程中的合作学习

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1135

R. Boehm

引用次数: 0

Thermal Margin Evaluation for FELI Fuel Assemblies During an Accidental Vessel Draining 意外容器排水过程中FELI燃料组件的热裕度评估

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1128

R. Ambrosek, F. W. Ingram, G. Hawkes, J. Sterbentz

引用次数: 0

Influence of Non-Isothermal Button Gage Surface Temperature in Heat Flux Measurement Applications 非等温按钮表表面温度在热流测量应用中的影响

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1107

David A. Zilles, R. Abhari

{"title":"Influence of Non-Isothermal Button Gage Surface Temperature in Heat Flux Measurement Applications","authors":"David A. Zilles, R. Abhari","doi":"10.1115/imece1999-1107","DOIUrl":"https://doi.org/10.1115/imece1999-1107","url":null,"abstract":"\u0000 Button gages have been extensively used to measure convective heat transfer coefficients in a number of short duration experiments. A button gage consists of a small insert made from an insulator material, typically Pyrex, with a thin film of Platinum active element painted on its surface. In a typical short duration experiment, gages are initially at the same temperature as the test article. As the flow is established, convective heat flux results in the surface temperature of the gage to rise much more rapidly than the surrounding metal walls. The influence of this non-isothermal wall condition on the local thermal boundary layer and hence the measured data is the focus of the present program.\u0000 A detailed experimental study of the influence of local non-isothermal conditions on the inferred heat flux from button heat-flux gages is performed. An existing wind tunnel capable of generating subsonic through transonic flow conditions has been modified to include an isothermal flat plate test section with a row of surface flush-mounted button heat-flux gages. In addition to the button gages, a uniform sheet of two-layered Kapton heat-flux gages, operating under isothermal conditions, are also applied to the flat plate surface. A detailed study of the uncertainties of experimental results is performed. As part of this study, flow Mach number and Reynolds number are varied and their relative significance upon the deviation in the response of the gages is quantified. The measured heat flux did show a deviation from the isothermal measured values. It is further shown that a correction term based on classical heat transfer theory will adjust the measured heat flux on the flat plate to match isothermal values for a range of Reynolds numbers and temperature ratios.","PeriodicalId":120929,"journal":{"name":"Heat Transfer: Volume 4","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115629361","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

Reduction of Fire Hazards Downwind of Wind-Driven Fires by Tree Barriers: Part IV — Numerical Simulation of Real-Scale Fires Located in Kobe City, Japan 通过树木屏障减少风驱动火灾的下风火灾危险:第四部分-日本神户市真实火灾的数值模拟

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1117

K. Satoh, H. Yoshihara, K. Sagae

引用次数: 0

Investigation of Thermal Conductivity of a Polymer Solution as Function of Shearing Rate 聚合物溶液热导率随剪切速率函数的研究

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1099

M. Kostic, H. Tong, Vapor Corp, A. Westinghouse

引用次数: 12

Surface Deformation and Thermal Convection in Electrostatically-Positioned Droplets Under Microgravity 微重力下静电定位液滴的表面变形和热对流

Heat Transfer: Volume 4 Pub Date : 1999-11-14 DOI: 10.1115/imece1999-1120

Su-Ae Song, Ben Q. Li

{"title":"Surface Deformation and Thermal Convection in Electrostatically-Positioned Droplets Under Microgravity","authors":"Su-Ae Song, Ben Q. Li","doi":"10.1115/imece1999-1120","DOIUrl":"https://doi.org/10.1115/imece1999-1120","url":null,"abstract":"\u0000 Electrostatically positioned droplets are very useful for the fundamental study of solidification phenomena and the measurement of thermal physical properties. This paper descries a numerical analysis of surface deformation and surface tension driven flows in electrostatically positioned droplets in microgravity. The analysis is based on a fully coupled boundary element and finite element solution of the Maxwell equations, the Navier-Stokes equations and the energy balance equation. Results show that an applied electrostatic field results in a nonuniform electric stress distribution along the droplet surface, which, combined with surface tension, causes the droplet to deform into an ellipsoidal shape in microgravity. Laser heating induces a non-uniform temperature distribution in the droplet, which in turn produces Marangoni convection in the droplet. It is found that the viscous stress contribution to the deformation is small for a majority of cases. Also, a higher temperature gradient produces a stronger Marangoni convection in droplets with higher melting points that require more laser power. The internal recirculating flow may be reduced by more uniform laser heating. During the undercooling of the droplet, both temperature and fluid flow fields evolve in time such that the temperature gradient and the tangential velocities along the droplet surface subside in magnitude and reverse their directions.","PeriodicalId":120929,"journal":{"name":"Heat Transfer: Volume 4","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126819316","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