Thermal performance of angled, V-shaped and leaning-V-shaped ribs in a rotating rectangular channel with 45° orientation

Abstract

Purpose The fluid flow in a rotating channel is obviously different from that in a stationary channel due to the existence of Coriolis force, which, in turn, enhances the heat transfer on the trailing side and reduces the heat transfer on the leading side. The purpose of this paper is to study various rib configurations combined with channel orientation on heat transfer and frictional loss in a rotating channel. Design/methodology/approach In the present study, the k-ω SST model was used as the turbulence model. The fluid flow direction in the channel is radially outward. The angle between the rotation axis and leading side is 45°. The channel aspect ratio (W/H) is 2, the blockage ratio (e/Dn ) is 0.1 and the pitch ratio (P/e) is 10. The Reynolds number is fixed at 10,000 and the rotation number varies from 0 to 0.7. Angled ribs, reversed angled ribs, standard V-shaped ribs and outer-leaning V-shaped ribs, are examined. Findings It is found that the reversed angled rib configuration and the outer-leaning V-shaped rib configuration display better heat transfer performance than the V-shaped ribs in rotating condition, which is in contrast to stationary condition. At the leading side, the reversed angled rib and the outer-leaning V-shaped rib show better performance in recovering the heat transfer recession due to the negative effects of the Coriolis force. Research limitations/implications In the present study, the fluid is incompressible with constant thermophysical properties and the flow is steady. Practical implications The results of this study will be helpful in design of ribbed channels internal cooling for turbine blade. Originality/value The results imply that the rib configuration combined with channel orientation significantly impacts the heat transfer performance in a rotating channel. The reversed angled rib and the outer-leaning V-shaped rib show better heat transfer performance than standard V-shaped ribs, especially at high Rotating numbers, which is in contrast to stationary condition. The outer-leaning V-shaped rib has a relatively good heat transfer uniformity along the widthwise direction.