Numerical study of turbulent flow and heat transfer in channels with detached pin fin arrays under stationary and rotating conditions

The effects of different detached pin fin configurations were investigated through numerical simulations on the heat transfer and flow structure in rectangular stationary and rotating channels at the Reynolds number range of 10,000-54,000 and the rotation number of 0.15. For the two kinds of detached pin fins, there existed clearances through the full-height pin fins, and the heights of the clearances were 20% of the full pin fins height. The present study focus on the enhancement of heat transfer and the pressure loss reduction with the application of detached pin fins. Moreover, the numerical simulations manifested much lower pressure loss and better heat transfer performance in the detached pin fin channels. The fluid flowed through the clearances producing additional transverse vortices in the wake region behind the pin fins, which greatly enhanced the heat transfer on the endwall downstream of the detached pin fins. Therefore, the uniformity of heat transfer performance on the endwall of the detached pin fin channels was superior to that of the full-height pin fin channels under stationary and rotating conditions. Additionally, the detached pin fin channels with two clearance configurations have decreased friction factors by up to 31.9% and increased overall heat transfer by up to 16.9%, which corresponded to an increase in the overall thermal performance parameters by up to 29.1% compared to the full-height pin-fin channel.