Turbulent Flow and Heat Transfer Characteristics of Novel Vortex Ribs in a Rotating Channel

Abstract

Heat transfer and pressure loss characteristics of a novel Vortex rib in a cooling channel have been studied both experimentally and numerically under the Reynolds numbers from 10,000 to 80,000 and rotation numbers from 0 to 0.385. The Vortex rib is proposed by combining W-rib and W-patterned oblong dimple. Compared with the W-rib, the Vortex rib enhances heat transfer by up to 11.4% (Re = 10,000 and Ro = 0.31) while reducing the pressure loss by up to 18.7% (Re = 32,000 and Ro = 0) under non-rotating and rotating conditions. Compared to the W-patterned oblong dimple, the heat transfer of the Vortex rib increases by up to 47.9%. The heat transfer dead zones are significantly improved by near-wall vortex induced by Vortex rib. The Vortex rib can appreciably reduce the turbulent mixing intensity in the mainstream of the cooling fluid but keep the near-wall high turbulent mixing intensity, guaranteeing the turbulent heat transport capacity. Thus, the heat transfer can be improved while maintaining the pressure loss in the channel.