Influence of surface heat flux ratio on heat transfer augmentation in square channels with parallel, crossed, and Vshaped angled ribs
Abstract
The paper investigates the effect of the wall heat flux ratio on the local heat transfer augmentation in a square channel with two opposite inline ribbed walls for Reynolds numbers from 15,000 to 80,000. The square channel composed of 10 isolated copper sections has a lengthtohydraulic diameter ratio of 20. The rib heighttohydraulic diameter ratio is 0.0625 and the rib pitchtoheight ratio equals 10. Six ribbed side to smooth side wall heat flux ratios are studied for four rib orientations. The results show that the ribbed side wall heat transfer augmentation increases with increasing ribbed side to smooth side wall heat flux ratios, but the reverse is true for the smooth side wall heat transfer augmentation. The average heat transfer augmentation of the ribbed side and smooth side wall decreases slightly with increasing wall heat flux ratios. The effect of wall heat flux ratio reduces with increasing Reynolds numbers. The 60deg Vshaped rib and 60deg parallel rib perform better than the 60deg crossed rib and 90deg rib, regardless of wall heat flux ratio and Reynolds number.
 Publication:

ASME Journal of Turbomachinery
 Pub Date:
 October 1992
 Bibcode:
 1992ATJTu.114..872H
 Keywords:

 Flow Geometry;
 Heat Flux;
 Heat Transfer Coefficients;
 Turbine Blades;
 Wall Flow;
 Aerodynamic Heat Transfer;
 Channel Flow;
 Ribs (Supports);
 Fluid Mechanics and Heat Transfer