An Experimental Study on Effusion Film Cooling Performance of Sand Dune-Inspired Hole Under Swirling Flow Condition

Abstract

Effusion film cooling is an essential technology applied to protect the aero-engine combustion chambers. In this study, a sand dune-inspired effusion cooling configuration under swirling flow was studied and compared with cylinder effusion cooling plate. The adiabatic film cooling effectiveness was measured by applying PSP (Pressure Sensitive Paint) technique and the flow field in the midplane was obtained by using PIV (Particle Image Velocimetry) technique. Four cases were studied for each configuration: when the pressure drop of the slot coolant was 3%, the pressure drop of the plate was set to 1%, 2% and 3% separately, and when the slot coolant was turned off, the pressure drop of the plate was set to 3%. With the slot on, the film effectiveness of the dune-inspired design increases about 20% in the upstream zone (x/D < 24) and 90% in the downstream zone (x/D > 24) compared to the circular hole. If the slot coolant is off, the film cooling effectiveness increases about 140% in both upstream and downstream zone. Based on the PIV results, the dune shells prevent the jets lifting-off thus the coolant film is better attached to the cooled wall.