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Showing papers by "Ephraim M Sparrow published in 1979"




Journal ArticleDOI
TL;DR: In this paper, the performance of the two types of segmented-plate arrays with each other and with the parallel-plate channel was compared. And the results depend on only a single dimensionless parameter which encompasses the relevant geometrical and fluid flow quantities.

73 citations


Journal ArticleDOI
TL;DR: In this paper, experiments were performed for freezing under conditions where the liquid phase is either above or at the fusion temperature (i.e., superheated or nonsuperheated liquid).
Abstract: Experiments were performed for freezing under conditions where the liquid phase is either above or at the fusion temperature (i.e., superheated or nonsuperheated liquid). The liquid was housed in a cylindrical containment vessel whose surface was maintained at a uniform, time-invariant temperature during a data run, and the freezing occurred on a cooled vertical tube positioned along the axis of the vessel. The phase change medium was n-eicosane, a paraffin which freezes at about 36/sup 0/C (97/sup 0/F). In the presence of liquid superheating, the freezing process is drastically slowed and ultimately terminated by the natural convection in the liquid. The terminal size of the frozen layer an the time at which freezing terminates can be controlled by setting the temperature parameters which govern the intensity of the natural convection. The stronger the natural convection, the thinner the frozen layer an the shorter the freezing time. In the absence of liquid superheating, a cylindrical frozen layer grows continuously as predicted by theory, but the growth rate is higher than the predictions because of the presence of whisker-like dendrites on the freezing surface.

68 citations



Journal ArticleDOI
TL;DR: In this article, photographic evidence of actual meh layer shapes was obtained to corroborate those inferred in [l], and photographs showed the melt Iayer both below and above the cylinder, thereby extending the results of [l] relevant to the role of natural convection in the melting of solids.

33 citations


Journal ArticleDOI
TL;DR: In this article, the average heat-transfer coefficients and the patterns of fluid flow for a square plate situated at various orientations to the flow direction were determined using the naphthalene sublimation technique.

27 citations





Journal ArticleDOI
TL;DR: In this article, the heat transfer characteristics for natural convection about an isothermal vertical cylinder with surface mass transfer (blowing or suction) were determined by analyzing the local nonsimilarity method, and solutions were obtained by a numerical scheme which employs integrated forms of the governing differential equations.


Journal ArticleDOI
TL;DR: Melting coefficients for an array of heating cylinders embedded in a eutectic mixture of NaNO/sub 4/ and NaOH were obtained for an AIP in this paper, where the cylinders were embedded in an EUTECTIC MOHA.
Abstract: Melting coefficients are obtained for an array of heating cylinders embedded in a eutectic mixture of NaNO/sub 4/ and NaOH. (AIP)


Journal ArticleDOI
TL;DR: In this paper, the authors considered laminar flow in a channel from which a blocked branch line emanates at right angles, and the channel and the branch line constitute a solution domain that is nonregular with respect to computer codes structured to deal with domains that are rectangular.
Abstract: Consideration is given to laminar flow in a channel from which a blocked branch line emanates at right angles. The channel and the branch line constitute a solution domain that is nonregular with respect to computer codes structured to deal with domains that are rectangular. As an application of a technique devised by Patankar, the nonregular domain was transformed into a rectangular domain within which the fluid experiences a stepwise change of viscosity, taking on infinite viscosity in regions where flow is not to exist. Numerical solutions were obtained for parametric values of the channel Reynolds number and of the dimensionless length of the blocked branch line. The results showed that the greatest disturbance of the main flow by the presence of the branch line occurs at low Reynolds numbers, but that the recirculation bubble in the branch line is more vigorous at high Reynolds numbers. The pressure drop in the channel is diminished by the presence of the branch line. The extent of the diminution is ...


Journal ArticleDOI
TL;DR: In this paper, a numerical solution for determining the temperature distribution along the exposed surface of a convectively cooled wall whose rear side is heated by a periodic array of groove-embedded heating elements is presented.
Abstract: Numerical solutions have been carried out to determine the temperature distribution along the exposed surface of a convectively cooled wall whose rear side is heated by a periodic array of groove-embedded heating elements. The accuracy of the numerical procedure was verified by using it to solve a related problem in which the heating occurs at discrete surface patches and then comparing those results with an exact solution. The numerical results for the exposed-surface temperature distributions corresponding to groove and patch heating were compared, and remarkably close agreement was found to prevail. This finding suggests that the computationally convenient exact solution for patch heating can be employed to obtain results for groove heating. The parameters which affect the uniformity of the temperature distribution on the convectively active surface were identified, and their quantitative influence was explored.