以某型发动机导向叶片中截面叶型的片体模型为研究对象,基于简化的冷气射流模拟方法分析了不同叶型位置、不同射流角度、不同孔径下的冷却射流与主流燃气的掺混损失和流量变化情况。通过与带有真实冷却气膜孔结构算例的对比,射流模型在压力面侧及吸力面前段可以较为准确地捕捉不同叶型位置处的流动损失变化情况,总压损失绝对值的最大偏差仅有0.02%,而在吸力面后段,射流法的分析结果则出现了较为明显的偏离。对不同倾斜角和孔径的分析结果表明,由于并未精确模拟气膜孔出口的肾形对涡,简化射流法在气膜孔出口附近低估了实际流动的损失,但随着流动的发展,冷却流动与主流流动沿流向的掺混损失占据主导,此时简化射流法可以较为准确地捕捉包括损失峰值在内的沿程流动损失变化情况。

Using a certain aero engine turbine mid-span cascade as object, a simplified jet-flow method has been established to analyze mixing losses and inlet mass flow rate on the variation of jet-flow positions, elevation angles, and hole diameters. By comparing with real cooling film hole model analyses, injection model can accurately capture the changes in flow losses on the pressure surface side and front section of the suction surface with a maximum absolute deviation of total pressure loss of 0.02%. However, analysis results show a significant deviation at the rear section of suction surface. Analyses on different elevation angles and hole diameters indicate that the simplified injection method tends to underestimate the actual loss near the gas film hole due to the lack of accurate simulation of the kidney-shaped vortex. As the injection flow develops, the mixing loss of cooling flow and mainstream flow along the flow direction becomes the dominant factor, the simplified jet-flow method can accurately predict the changes of losses along the stream, including position of the loss peak.

V231.3

国家科技重大专项（2019-II-0008-0028）