Heat transfer in a rotating smooth wedge-shaped channel with lateral fluid extraction

Abstract

In the current study, a rotating smooth wedge-shaped channel with lateral fluid extraction is experimentally investigated. Experiments are conducted at four different Reynolds numbers (from 5100 to 21,000) and five different rotational speeds (from 0 to 1000 rpm), which results in the inlet rotation number varying from 0 to 0.68. In order to study the effects of channel orientation and outlet boundary condition, experiments are conducted at five different channel orientations and two types of boundary conditions. Based on the obtained experimental data, it is concluded that channel orientation strongly influences the rotational effects on flow and heat transfer characteristics. The sensitivity of the channel orientation on wall heat transfer is analyzed. Unexpectedly, outlet boundary condition affects heat transfer characteristics under non-rotating conditions but has almost no effect at high rotational speeds. The general rotation number is better than the local one to describe the flow status. The critical inlet rotation numbers, after which the descending trends of Nusselt number ratios are reversed, are around 0.3 at all the locations. Also, rotation reduces leading-to-trailing averaged Nusselt ratios and affects heat transfer characteristics more evidently on the inner wall than the outer one, and on the low-radius wall than the high-radius one.