Numerical Investigation on Heat Transfer and Flow Characteristics of Combined Pin-Fin With Rib in a Rectangular Channel

Abstract

Abstract In this paper, numerical simulation has been conducted to investigate the heat transfer and flow characteristics for cooling schemes which combine pin-fins and ribs. A pin-fin internal cooling channel with an aspect ratio 4:1 was used as baseline, where the pin-fin height-to-diameter ratio was H/D = 2.5, and both streamwise and spanwise spacing were S/D = 2. The combined cooling schemes use partitioned strip ribs to replace part of pin-fins in the rectangular channel. The number of partitioned strip rib is 2, 3, 4 and 4 in Case A, Case B, Case C and Case D, respectively. Simulations were performed at five Reynolds numbers between 7300 and 36000. The results show that the combined cooling schemes bring higher heat transfer, but also produce higher pressure loss. The addition of ribs effectively extends the endwall heat transfer area. The higher blockage ratio of channel sharply increases the pressure loss while enhances heat transfer. Comparing to the baseline pin-fin channel, the overall thermal performance of Case A, Case B, Case C and Case D increases 6.2%, 12.2%, 21.9% and 39.2% respectively, at the Reynolds number of 22,000. The combined cooling scheme could be used in situations where higher cooling load is required and the pressure drop is not of much concern.