扭转度误差对跨声速压气机叶片性能的影响

Effects of Twist Angle Error on Transonic Compressor Blades Performance

关键词:  跨声速压气机叶片  扭转度  加工误差  稳定工作裕度  激波

Key words:  Transonic compressor blade  Twist angle  Machining error  Stable working margin  Shock wave

摘要:

在压气机叶片加工过程中，受切削力等因素影响扭转变形不可避免。为探究扭转度误差对叶片气动性能的影响，将实测某压气机叶片扭转度误差数据应用于Rotor 37转子，创建误差叶片，通过数值模拟获得其设计转速下的性能参数。结果表明：相较于原叶片，“欠偏转”叶片特性曲线整体向小流量工况移动，反之，“过偏转”叶片特性曲线则向大流量工况移动，且各方案对应误差叶片的气动性能均合格；在设计工况下，随扭转度误差变化，总压比较等熵效率变化更显著，其中“欠偏转”叶片总压比减小，最大变化量为0.85%；此外，相较于原叶片，“欠偏转”叶片稳定工作裕度增大，其最大变化量可达12.29%，同时，“欠偏转”叶片通道激波延后，流动损失减小，且叶顶低速区范围减小，即在公差范围内，负扭转度误差对气流流动状态具有一定改善作用。

Abstract:

In the process of compressor blade machining， twist deformation is inevitable due to cutting force and other factors. To explore the effects of twist angle error on blade aerodynamic performance， the measured twist angle error of a compressor blade was applied to Rotor 37 to create the blades with error， and the performance parameters under the design rotating speed were obtained by numerical simulation. The results show that： compared with the original blade， the characteristic curve of under-deflection blades moves to the low-flow condition as a whole， which moves to the high-flow condition as the blades are over-deflection. And the aerodynamic performance of the corresponding blades of each twist scheme is qualified. Under the design condition， the total pressure ratio changes more significantly than the isentropic efficiency with twist angle error changing， and the total pressure ratio decreases when the blades are under-deflection whose maximum variation is 0.85%. Additionally， the stable working margin increases when the blades are under-deflection， whose maximum variation is 12.29% compared with the original blade. At the same time， the channel shock wave is delayed， the flow loss is reduced， and the range of low-speed area at the blade tip decreases as the blades are under-deflection. It indicates that the negative twist angle error within tolerance has a certain improvement effect on the flow condition.