气膜孔角度对突肩叶尖泄漏和冷却特性的影响

Effect of Film Hole Angle on the Tip Leakage Flow and Cooling Characteristics of Squealer Tip

通过数值模拟的方式对不同气膜孔角度下突肩叶尖的相对泄漏流量、间隙泄漏损失和叶尖气膜冷却效率进行了对比研究。结果显示:气膜孔带有展向角度相比流向角度的相对泄漏流量略大,这是因为气膜孔有展向角度时,前缘气膜孔的倾斜方向与泄漏流方向一致,对泄漏流的阻碍作用较小。气膜孔流向角度会使所有气膜孔下游的气膜冷却效率大幅增加,但冷却气体对凹槽底面最前缘的覆盖减小;气膜孔展向角度会使所有气膜孔下游的气膜冷却效率大幅增加,特别是在中弦区域,还会使得尾缘处的高气膜冷却效率区域更加靠近叶片压力侧。

The relative leakage flow rate,tip leakage loss and film cooling effectiveness of squealer tip with different film hole angles were studied by numerical simulation.The results show that the relative leakage flow rate of the film hole with span wise angle is slightly larger than that with the stream wise angle.It is because when the film hole has span wise angle,the inclination direction of the leading edge film holes are the same as that of the leakage flow,and the blockage effect on the leakage flow is small.The stream wise angle of the film holes will greatly increase the film cooling effectiveness downstream of all the film holes,but the coverage of the cooling air on the leading edge of the blade bottom will decrease.The span wise angle of the film holes will greatly increase the film cooling effectiveness downstream of all the film holes,especially in the middle chord region,and the high film cooling effectiveness area at the trailing edge will be closer to the blade pressure side.