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Showing papers by "Ephraim M Sparrow published in 2003"



Journal ArticleDOI
TL;DR: In this paper, an experimentally motivated numerical simulation of three-dimensional natural convection in a heated enclosure containing a discrete thermal load has been performed, where a special feature of the simulation is the use of the actual equation of state of air, in contradistinction to the customary Boussinesq model.
Abstract: An experimentally motivated numerical simulation of three-dimensional natural convection in a heated enclosure containing a discrete thermal load has been performed. A special feature of the simulation is the use of the actual equation of state of air, in contradistinction to the customary Boussinesq model. Heating is accomplished continuously at all the walls of the enclosure and by a discrete, rod-like heater situated at the enclosure floor. The bulk of the solutions were carried out for steady laminar flow, but a specific solution for turbulent flow was performed for comparison purposes. By making use of an extended quasi-steady model, the steady-state results were employed to predict the time-varying temperature of the thermal load. The agreement between the numerically based predictions and the experimental data obtained by the authors was very good. For the case selected for the laminar-turbulent comparison, only modest deviations occurred for the heat transfer rates at the surfaces of the load. It ...

28 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a computational method that implements an analytical approach toward determining the thermal processes that take place in an electrically heated oven, where integral equations of radiative heat transfer are specialized to the three-dimensional temperature field in the oven and numerically evaluated.
Abstract: This article presents a computational method that implements an analytical approach toward determining the thermal processes that take place in an electrically heated oven. The integral equations of radiative heat transfer were specialized to the three-dimensional temperature field in the oven and numerically evaluated. The radiative fluxes at the surfaces of a thermal load situated in the oven were thus obtained and combined with natural convection fluxes extracted from a well-established correlation. The net result was a set of predictions for the temperature history of a thermal load of which size, material properties, radiative surface characteristics, and location in the oven were varied. In addition, two modes of oven operation were considered: a preheated and a non-preheated oven. An alternative model for the experimental data was built on an algebraic representation utilizing a one-term, time-based exponential. That model enabled the identification of the effect of the thermal inertia factor; load...

14 citations


Proceedings ArticleDOI
01 Jan 2003
TL;DR: In this paper, the authors used the Design of Simulation (DOS) method to guide and enhance a numerical simulation of fluid flow and heat transfer through offset-fin arrays which form the interior geometry of a cold plate.
Abstract: The method of Design of Simulation (DOS) was used to guide and enhance a numerical simulation of fluid flow and heat transfer through offset-fin arrays which form the interior geometry of a cold plate. The basic problem involved 11 independent parameters. This prohibitive parametric burden was lessened by the creative use of nondimensionalization that was brought to fruition by a special transformation of the boundary conditions. Subsequent to the reduction of the number of parameters, the DOS method was employed to limit the number of simulation runs while maintaining an accurate representation of the parameter space. The DOS method also provided excellent correlations of both the dimensionless heat transfer and pressure drop results. The results were evaluated with respect to the Colburn Analogy for heat and momentum transfer. It was found that the offseting of the fins created a larger increase in the friction factor than that which was realized for the dimensionless heat transfer coefficient.@DOI: 10.1115/1.1800531#

4 citations