Investigation on Film Cooling Performance of the Compound Hole and Y-Shaped Hole Configurations With the Cross-Flow Coolant Channel

Film cooling performance of the compound hole and the Y-shaped hole configurations with the cross-flow coolant channel is investigated experimentally and numerically in this paper. The Reynolds numbers of coolant flow are fixed as 50000 and 100000 respectively. The film cooling effectiveness and heat transfer coefficient were measured by the transient liquid crystal measurement technique under three blowing ratios of 0.5, 1.0 and 2.0 respectively. And flow resistance measurements were also performed to obtain the discharge coefficient of the two film hole configurations. Numerical simulations with Reynolds-averaged Navier-Stokes (RANS) method were performed to explain the experiment results. The results show that the distribution feature of film cooling effectiveness for the compound hole and Y-shaped hole configurations is different. The film cooling effectiveness of the Y-shaped hole configuration is higher than that of the compound hole, and the film spanwise coverage is larger than that of the compound hole under all cases. For two film hole configurations, the heat transfer coefficient increases with the increase of the cross-flow Reynolds number and the blowing ratio. The heat transfer coefficient of the compound hole and Y-shaped hole configurations is close to each other under small cross-flow Reynolds number. However, under large cross-flow Reynolds number, the compound hole configuration has much higher heat transfer coefficient. The discharge coefficient increases gradually with the rising blowing ratio, then tend to a fixed value. Under the condition of the small cross-flow Reynolds number, the discharge coefficient of two film hole configurations is high. The discharge coefficient of the Y-shaped hole configuration is a little higher than that of the compound hole configuration under the condition of the large blowing ratio.