Experimental and Numerical Studies for a Surrogate-based Optimized Guiding Pin-fin Heat Transfer in Rotating Wedge-shaped Trailing Edge Channel

Abstract In this study, rotational experiments are performed on a newly constructed rotating test rig using a wedge-shaped channel equipped with conventional circular pin-fin (CP) arrays and optimized guiding pin-fin (OGP) arrays. Numerical simulations are further employed to analyze the internal flow and heat transfer mechanisms. The experimental conditions cover Reynolds numbers ranging from 10,000 to 50,000 and rotation numbers from 0 to 0.3. At a Reynolds number of 10,000 under stationary conditions, the CP and OGP arrays exhibit comparable heat transfer performance. As the rotation number increases, the OGP array demonstrates appreciably improved heat transfer than the CP array. Under other tested conditions, the channel-averaged Nusselt number of the OGP array is 5% to 8% higher than that of the CP array. The experiments also show that under rotations, the leading surface heat transfer of CP array remains almost unchanged or slightly decreases relative to the stationary case, whereas the trailing surface experiences a noticeable enhancement by about 15%. However, the novel OGP array shows robust optimization with the consistent heat transfer improvement on both the leading and trailing surfaces under rotations. Further CFD results reveal that the OGP array achieves a more uniform coolant distribution across the entire internal cooling passage. As a result, the big portion area with high wall temperature is markedly reduced in the mid-span and tip regions of the channel by the OGP array, where the CP array exhibits inferior heat transfer performance there.