透平级小翼-凹槽叶顶冷却传热性能研究

Investigations Into Film Cooling and Heat Transfer Performance on Winglet-Squealer Tips in a Turbine Stage

采用数值方法研究了发动机工况下含内冷通道的透平级小翼-凹槽叶顶的冷却传热性能,分析了叶顶型式、吹风比对叶顶传热系数和气膜冷却效率分布的影响。结果表明:带压力侧小翼凹槽叶顶可有效消除叶顶刮削涡,改善凹槽底部冷气覆盖的均匀性;相对于传统凹槽叶顶,带压力侧小翼凹槽叶顶的面积平均传热系数减小11.11%、气膜冷却效率增大4.54%。吹风比从1增大到2时,带压力侧小翼凹槽叶顶面积平均传热系数减小48.96%、气膜冷却效率增大154.01%。

Film cooling and heat transfer performance on the winglet-squealer tip of a turbine stage with internal cooling channels were numerically investigated under engine condition.The effects of tip geometry and blowing ratio on the heat transfer coefficient and film cooling effectiveness distributions on the squealer tip were analyzed.The results showed that the existence of pressure-side winglet is able to eliminate the scrapping vortex in tip gap,thus improving the uniformity of coolant coverage on the squealer cavity floor.Compared to the conventional squealer tip,the area-averaged heat transfer coefficient is reduced by 11.11%and the area-averaged film cooling effectiveness is increased by 4.54%for the pressure side winglet-squealer tip.As the blowing ratio increases from 1.0 to 2.0,the area-averaged heat transfer coefficient on the winglet-squealer tip is reduced by 48.96%,and the area-averaged film cooling effectiveness on the winglet-squealer tip is improved by 154.01%.