Forced Convection Heat Transfer Coefficient Research Articles

Transient Forced Convection Heat Transfer to Helium During a Step in Heat Flux

Transient forced convection heat transfer coefficients for both subcritical and supercritical helium in a rectangular flow channel heated on one side were measured during the application of a step in heat flux. Zero flow data were also obtained. The heater surface which served simultaneously as a thermometer was a fast response carbon film. Operating conditions covered the following range: Pressure, 1.0 × 105 Pa (1 bar) to 1.0 × 106 Pa (10 bar); Temperature, 4 K–10 K; Heat Flux, 0.1 W/cm2−10 W/cm2; Reynolds number, 0–8 × 105. The experimental data and a predictive correlation are presented.

Heat-transfer measurements in the moving-wire technique for studying polymer flammability

A new technique was developed for measuring the laminar forced-convective heat-transfer coefficient from a hot gas to a wire, even in the presence of concurrent radiant heating. The method is especially suited for applications to the moving-wire technique (MWT) for studying polymer combustion [1]. In the MWT, a polymer is first coated on a fine wire (or fiberglass yarn) and then pulled in the direction of its axis across the O 2-rich wake of a premixed gas-burner flame. The technique produces a steady polymer flame convenient for chemical studies. The heat-transfer coefficient from the burner flame to the coated wire can be measured by pulling a comparably sized wire thermocouple across the burner in the same way. Its rate of temperature rise determines the heat-transfer coefficient. Heat transfer was measured in three steady laboratory-scale heat sources. The first was a stream of hot N 2, in which it was shown that the measured value of the coefficient was consistent with correlations in the literature, thus validating the technique. Measurements were then made in the wake of a CH 4O 2 flame, and inside a blackbody oven, where radiation and convection both occurred.

The Thermal Design of an LSI Single-Chip Package

Theoretical and experimental methods are used to predict the thermal properties of an air-cooled integrated-circuit package with a large LSl type of chip. A previously reported three-dimensional solution to the differential equation for steady-state heat transfer has been extended to include composite media with up to four layers of unequal thickness and thermal conductivity. The theoretical results are used to calculate the detailed thermal characteristics of a 1.3 X 0.6-in package with a 0.17-in square chip. Geometric and physical considerations include the effects of ceramic thickness and thermal conductivity, chip dimensions, lead conduction, and heat-sink variations. An empirical technique is used to determine the forced-convection heat-transfer coefficients for a variety of extruded aluminum heat sinks. The effects of fin length, air velocity, and number of fins per inch are measured.

Computer-Aided Thermal Design of LSI Packages

Forced convection cooling with direct air impingement on modules mounting LSI hybrid packs is analyzed with one comprehensive thermal mode. A matrix solution for a steady state nodal conductance network is used to predict the temperature rise of the coolant flowing over the module and substrate-to-inlet air temperature differentials. To allow the utilization of a fine nodal mesh to model a hybrid substrate and yet limit the nodal network to a matrix size which can be inexpensively solved by computer, a method is presented to simulate hybrid substrates using equivalent conductances. The problem of determining the forced convection heat transfer coefficient in a module cooling channel where the hermetically sealed hybrid substrates act as protuberances is addressed. Analytical prediction ,of substrate-to-inlet air temperature differences obtained from the thermal model is favorably compared with experimental measurements.

Enhancement of Forced Convection Heat Transfer Coefficient Using Detached Turbulence Promoters

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEnhancement of Forced Convection Heat Transfer Coefficient Using Detached Turbulence PromotersD. G. ThomasCite this: Ind. Eng. Chem. Process Des. Dev. 1967, 6, 3, 385–390Publication Date (Print):July 1, 1967Publication History Published online1 May 2002Published inissue 1 July 1967https://doi.org/10.1021/i260023a022RIGHTS & PERMISSIONSArticle Views171Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts