单级轴流压气机确定应力场计算精度分析

Calculation Accuracy Analysis of Deterministic Stress Field in Single-Stage Axial Flow Compressor

关键词:  轴流压气机  非定常  确定应力  相位延迟  叶片约化  非线性谐波法

Key words:  Axial flow compressor  Unsteady  Deterministic stress  Phase lag  Domain scaling  Nonlinear harmonic method

摘要:

为分析各非定常模拟方法对于确定应力场的计算精度以便为确定应力的建模与校准提供指导，以Stage35单级轴流压气机为研究对象，分别用相位延迟法、叶片约化法及非线性谐波法对其进行了非定常数值模拟，并将得到的确定应力分布与半环常规非定常模拟进行对比。结果表明:非线性谐波法对于确定应力的预测值通常偏大，而相位延迟法及叶片约化法均能较准确地捕获流场确定应力分布，但对于确定应力的周向变化，三种方法的预测精度均不高；谐波阶数的增加有助于提高非线性谐波法对于流场频谱特征的计算精度，并且使确定应力有增大趋势，但对时均参数的预测精度影响很小。

Abstract:

In order to analyze the precision of different unsteady simulation methods in prediction of deterministic stress field and provide guidance for the determining stress modeling and calibration，the deterministic stress obtained using the nonlinear harmonic，phase lag and domain scaling method respectively are compared to results predicted by a conventional half annulus unsteady simulation. Numerical results indicate that the nonlinear harmonic method usually obtains higher deterministic stress，phase lag and domain scaling method can all achieve high accuracy level in prediction of deterministic stress field，however，both three solutions fail to accurately capture the circumferential distribution of that. By including more number of harmonics，the calculation precision of frequency-spectrum characteristics gained with nonlinear harmonic method can be improved，and a growing trend in deterministic stress can be observed also，whereas it has a negligible effect on the prediction accuracy of time-averaged parameters of flow field.