冷却气进气角度对端壁泄漏流气膜冷却特性影响

Influence of coolant inlet angle on endwall leakage flow film cooling performance

基于叶盘一体化模型,通过使用切应力输运(SST)模型对雷诺平均Naiver-Stokes(RANS)方程进行求解的方式研究了涡轮叶片端壁泄漏流气膜冷却特性,盘腔出口处的旋转雷诺数为1.5×10^(5)。为保证冷气与主流的密度比,冷却气使用二氧化碳来模拟,其在盘腔和主流中的扩散通过求解湍流输运方程得到。通过传质模拟传热的方式研究了由二级导向器进入盘腔的冷却气进气角度(-45°,0°,+45°)对端壁绝热气膜冷却效率的影响。研究发现:改变冷却气进气角度对端壁冷却特性影响明显,-45°进气角度能明显提高各冷却气与主流质量流量比下的端壁气膜冷却效率。

By using an integrated model with disc cavity and turbine blade,the endwall film cooling effectiveness was investigated numerically by using the shear stress transfer(SST) model to solve the Reynolds-averaged Naiver-Stokes(RANS) equation.The rotational Reynolds number at the outlet of the disc cavity was 1.5×10^(5).Carbon dioxide was chosen as the coolant to maintain the coolant-to-mainstream density ratio.The diffusion process of coolant was characterized by solving the turbulent transport equation.The effect of coolant inlet angle(-45°,0°,+45°) on the endwall film cooling effectiveness was investigated.It was found that the inlet angle of coolant had a significant impact on the endwall film cooling effectiveness,and the-45° inlet angle can significantly improve the endwall film cooling effectiveness at various coolant-to-mainstream mass flow rates.