Showing papers by "Ephraim M Sparrow published in 1982"
TL;DR: In this article, a multi-faceted experimental investigation has been carried out to study heat transfer and pressure drop for airflow in arrays of heat generating rectangular modules deployed along one wall of a flat rectangular duct.
213 citations
130 citations
82 citations
TL;DR: In this paper, a phase-change medium in a vertical tube was used to study the effect of fluid motions in the liquid melt induced by volume change and natural convection, with the former being significant only at early times.
Abstract: Experiments on the melting of a phase-change medium in a vertical tube yielded quantitative results both for the heat transfer and the timewise evolution of the melting front. The upper surface of the phase-change medium was bounded by an insulated air space, which accommodated the volume changes which accompany the melting process. Numerical solutions based on a pure conduction model were also performed for comparison purposes. It was found that the rate of melting and the heat transfer are significantly affected by fluid motions in the liquid melt induced by the volume change and by natural convection, with the former being significant only at early times. For melting initiated with the solid at the phase-change temperatures, the experimentally determined values of the energy transfer associated with the melting process were about 50 percent higher than those predicted by the conduction model. Furthermore, the measured values of the energy stored in the liquid metal were about twice the conduction prediction. A compact dimensionless correlation of the experimental results was achieved using the Fourier, Stefan, and Grashof numbers. Initial subcooling of the solid substantially decreased the rate of melting, with corresponding decreases in the energy transfers for melting and sensible heat storage.
79 citations
TL;DR: In this article, a regular array of hexagonal holes are arranged on equilateral triangular centers, and this regular geometry gives rise to a symmetry pattern whereby each hole is surrounded by a hexagonal region, the boundaries of which are symmetry lines.
62 citations
TL;DR: In this paper, experiments were performed to determine per-fin heat transfer coefficients for pin-fin arrays exposed to a novel airflow arrangement, where flow enters the array longitudinally but, owing to the blocking action of the fin base surface, is forced to turn and exit the array with a predominantly crossflow orientation.
49 citations
41 citations
22 citations
TL;DR: In this paper, heat transfer coefficients for cylindrical and base surfaces of a cup-like rotating cavity were determined experimentally for three cavity length-diameter ratios and rotational Reynolds numbers which covered a fifteen-fold range.
19 citations
TL;DR: In this paper, an analysis has been made of the fluid flow and heat transfer in a vertically oriented cylindrical enclosure in whose lower and upper walls there are small apertures through which fluid passes into and out of the enclosure.
17 citations
TL;DR: Numerical finite difference solutions were carried out for natural convection in the enclosed space between two concentric vertical cylinders, with each cylinder being maintained at a different uni....
Abstract: Numerical finite-difference solutions were carried out for natural convection in the enclosed space between two concentric vertical cylinders, with each cylinder being maintained at a different uni...
TL;DR: In this paper, the authors performed both heat transfer measurements and flow visualization for cross-flow arrays of cylinders in which there is a missing cylinder and found that a staggered array is more responsive to missing cylinders than is an in-line array.
TL;DR: In this paper, a system consisting of two parallel vertical channels that share a common wall across which heat is transferred from one channel to the other is considered, and a solution scheme is employed in which each channel was visited successively and iteratively.
Abstract: Consideration is given to a system consisting of two parallel vertical channels that share a common wall across which heat is transferred from one channel to the other. The other walls of the system are characterized by prescribed surface temperatures that exceed the ambient temperature, and this induces a buoyancy-driven upflow in the channels. To cope with the strong interaction between the channels, a solution scheme was employed in which each channel was visited successively and iteratively. The single-channel solutions that were performed at each visitation were also iterative in character, with the computations carried out with a parabolic finite-difference method. Three parameters were varied during the course of the computations. These Included the dimensionless channel height, a dimensionless temperature difference, and the dimensionless position of the common wall between the channels. Results are presented for the surface-integrated heat transfer at each channel wall, the total system ...
TL;DR: In this article, the authors performed wind tunnel experiments to determine forced convection heat transfer coefficients for the leeward face of a roof-like structure, including a flat plate collector and an adiabatic frame.