Augmented heat transfer in rectangular channels of narrow aspect ratios with rib turbulators

The effects of the rib angle-of-attack on the distributions of the local heat transfer coefficient and on the friction factors in short rectangular channels of narrow aspect ratios with a pair of opposite rib-roughened walls are determined for Reynolds numbers from 10 000 to 60 000. The channel width-to-height ratios are 2 4 and 1 4; the corresponding rib angles-of-attack are 90°, 60°, 45°, and 30°, respectively. The results indicate that the narrow-aspect-ratio channels give better heat transfer performance than the wide-aspect-ratio channels for a constant pumping power. Semi-empirical friction and heat transfer correlations are obtained. The results can be used in the design of turbine cooling channels of narrow aspect ratios. © 1989.

Augmented heat transfer in rectangular channels of narrow aspect ratios with rib turbulators Academic Article