Film Cooling over Eroded Plates for the Injection of Air–Water Mist Coolant

Abstract

A computational analysis was carried out on the film cooling technique over the surfaces of eroded plates. The air–water mist coolant was injected through the slotted hole. A flat plate was patterned with various erosions. The loading fraction, f = 4–16%, and blowing ratio, M = 1–1.6, were simulated to understand their influence on the mist film cooling effectiveness. The coolant injection angle or the inclined angle of the secondary slot was kept at α = 35°. It can be observed that the increasing loading fraction raises the film cooling performance. Likewise, a higher blowing ratio can provide a better film cooling over the target surface. Again, it is found that the presence of erosion increases the cooling effectiveness at the particular surface of erosion. Simultaneously, a decrease in the effectiveness can also be noticed at the adjacent flat surfaces. Additionally, the erosions at the further downstream are more effective over the eroded surface compared to the upstream erosions. Considering the size of erosion as a crucial parameter, it was investigated for three different depth sizes. An increment in the mist film cooling performance is observed for the higher depth erosion.