Research of manufacturing errors on aerodynamic performance uncertainty of compressor rotor

加工偏差对压气机转子气动稳定性影响的不确定性研究

Naval Architecture and Ocean Engineering College, Dalian Maritime University, Dalian 116026, China

Received: 21 June 2024

Abstract

To investigate the impact of manufacturing errors on the stability of the compressor operation, a geometric uncertainty reduced order model is developed by generating the normal manufacturing error of blade profile and considering the correlation of blade profile. The stability margin improvement of the compressor was then calculated by using the computational fluid dynamics (CFD), and the neural network was used to predict the relationship between the uncertainty input variables and the stability margin improvement. Finally, a large number of samples were generated by using the Quasi-Monte Carlo method, and Sobol sensitivity analysis was performed. The results show that although the average value of the stability margin under the impact of manufacturing errors is almost equal to the design value, manufacturing errors can reduce the stability margin by about 3% in the limiting case. The parameters that have the greatest impact on the stability of the compressor are the blade chord length of the hub section and the maximum thickness of the tip section and they affect the blade tip blockage by influencing spanwise secondary flow on the suction surface. Furthermore, the results also demonstrate that the decrease in maximum thickness at the tip section affects the separation of the boundary layers on the suction surface, resulting in additional effects.

摘要

为了研究叶片加工偏差对压气机稳定性的影响，在构建叶片表面加工偏差的同时考虑了叶型轮廓间的相关性从而建立了一种几何不确定性降阶模型。通过CFD计算裕度改进量后使用神经网络预测不确定输入变量与裕度改进量的关系。使用伪蒙特卡洛方法生成大量样本并进行敏感性分析。此外，根据敏感性分析的结果，进一步观测流场的细微变化来了解加工偏差影响压气机稳定性的机理。结果表明：尽管在加工偏差作用下稳定裕度平均值几乎等同于设计值，但考虑极限情况下加工偏差可使稳定裕度下降约3%。对稳定裕度影响最明显的2个参数分别是叶根弦长和叶顶最大厚度，它们通过影响叶片吸力面的径向二次流进而影响叶顶的堵塞。此外，还观察到叶顶最大厚度的减小还会影响吸力面的附面层分离从而产生额外影响。