The Effect of Pore Size on the Heat Transfer Between a Heated Finned Surface and a Saturated Porous Plate

An investigation was performed to examine the effect that the pore size in a porous plate had on the heat transfer between a heated finned surface and a saturated porous plate at different gap distances between the surfaces. Experiments were performed for a porous plate with a nominal pore size of 50μm and the results were compared with previous results for a pore size of 200μm (Schertzer et al., 2006, “The Effect of Gap Distance on the Heat Transfer Performance Between a Finned Surface and a Saturated Porous Plate,” Int. J. Heat. Mass Transfer, 4, pp. 4200–4208). The plate with the smaller pore size performed better at small and intermediate gaps but not at large gaps. The maximum heat transfer coefficient was similar for both plates when compared in terms of the ratio between the gap distance and the pore size. However, the temperature distributions on the heated foil and their evolution with heat flux were dissimilar when compared in terms of the gap distance or the gap to pore ratio, suggesting that the boiling dynamics within the gap does not scale with either parameters.