Free convection across inclined air layers with one surface Vcorrugated
Abstract
Experimental measurements are presented for free convective heat transfer across inclined air layers, heated from below, and bounded by one Vcorrugated plate and one flat plate. The measurements covered three values for the ratio A (averaged plate spacing to Vheight), namely, A = 1, 2.5 and 4. They also covered angles of inclination with respect to the horizontal of 0, 30, 45 and 60 deg, and a Rayleigh number range of (104) million. The study proves, both theoretically and experimentally, that the free convective heat transfer is essentially the same, regardless of whether the Vcorrugated plate is above or below. It was found that for the same average plate spacing, L, the convective heat losses across air layers bounded by one Vcorrugated and one flat plate are greater than those for two parallel flat plates by up to 50 percent for the range studied. Experimental results are given as plots of Nusselt number versus Rayleigh number. A correlation equation is given for Nusselt number, Nu, as a function of the abovementioned parameters.
 Publication:

ASME Journal of Heat Transfer
 Pub Date:
 August 1978
 Bibcode:
 1978ATJHT.100..410E
 Keywords:

 Convective Heat Transfer;
 Free Convection;
 Solar Collectors;
 Surface Roughness Effects;
 Corrugated Plates;
 Flat Plates;
 Nusselt Number;
 Rayleigh Number;
 Fluid Mechanics and Heat Transfer