Velocity Measurements and Local Heat Transfer in a Rotating Ribbed Two-Pass Square Channel With Uneven Wall Heat Flux

Abstract

The influence of rotation and uneven wall heat flux effect on the local velocity distribution as well as local heat transfer coefficient in a rotating, two pass rib roughened (rib height e/DH = 0.20; rib pitch p/e = 5) square channel were studied for Reynolds numbers from 5000 to 10000 and rotation numbers from 0 to 0.1602 (≤ 300 rpm). The measured mean velocity under different wall heat flux condition for the specified rib configuration at ReH = 5000 and 10000, ReH = 0, 267, 534 and 801 are presented. Regionally averaged Nusselt number variations with rotation (≤ 800 rpm)along the duct have been determined over the trailing and leading surfaces for a two pass channel. Moreover, LDV measurements with heating were examined. It was found that the Coriolis force as well as centrifugal buoyancy is significant as the rotational speed increases.