端壁倒圆半径误差对高负荷静叶栅性能影响的不确定性分析

Uncertainty analysis of effects of end wall fillet radius error on high-load stator cascade performance

为对压气机静子叶片高精度设计与制造提供有力参考,以某高负荷压气机静子叶栅为研究对象,采用基于高斯分布型随机输入的非嵌入式多项式混沌方法,量化评估了端壁倒圆半径误差对最小损失和近失速两个工况下气动性能的不确定性影响。结果表明:倒圆半径误差的不确定性对气动性能的平均水平影响不大,主要反映在气动性能参数的标准差上。提高倒圆半径的加工精度可提升气动性能的鲁棒性近一倍。加工精度一定时,为对叶片进行鲁棒性优化设计,应重点关注近失速工况下气动损失的鲁棒性。根据公差带内端壁倒圆半径与近失速工况下气动性能的关联性分析,倒圆半径与气动性能呈线性关系,应避免倒圆半径与设计值相比偏小的叶片投入使用,以期获得良好的气动性能。通过近失速流场的不确定性分析,分离流动对于倒圆半径误差更为敏感,是引起气动性能不确定性变化的主要因素。

To provide a strong reference for the high-precision design and manufacture of the compressor stators,a high-load compressor stator cascade was used as the research object,and the non-intrusive polynomial chaos method based on Gaussian random input was used to quantitatively evaluate the uncertainty effect of the end wall fillet radius manufacturing error on the aerodynamic performance under the minimum loss and near stall conditions.Results showed that the uncertainty of the fillet radius error had little effect on the average level of aerodynamic performance,which was mainly reflected by the standard deviation of aerodynamic performance parameters.The robustness of aerodynamic performance can be nearly doubled by increasing the manufacturing accuracy of the fillet radius.When the manufacturing accuracy was constant,the robustness of total pressure losses under near stall conditions should be focused on to conduct the robustness design of the blade.According to the correlation analysis between the end wall fillet radius in the tolerance zone and the aerodynamic performance under near stall conditions,the fillet radius had a linear relationship with the aerodynamic performance,and it was required to avoid the use of blades with a rounding radius smaller than the nominal so as to obtain better aerodynam-ic performance.Through the uncertainty analysis of the near stall flow field,the separated flow was more sensitive to the rounding radius manufacturing error,which was the main factor causing the uncertainty of the aerodynamic performance.