压气机环形叶栅尾迹特性试验与数值模拟研究

Experimental and Numerical Investigation of the Wake Characteristics in an Annular Compressor Cascade

尾迹特性是影响轴流压气机损失和气动稳定性的重要因素。采用带进、出口导流叶片的环形叶栅试验方法对轴流压气机叶片尾迹进行了详细的流场测量,并结合数值模拟手段对尾迹损失进行了分析。环形叶栅试验和数值模拟结果对比表明,SST湍流模型的稳态计算结果与试验结果更加吻合,对尾迹的预测更为准确。环形叶栅出口截面尾迹损失沿径向分布不均匀,在20%50%叶高范围具有较高总压损失,在30%叶高处达到损失极值,其主要来源于下端壁边界层低速流体在叶片中后部沿着吸力面的径向迁移。通过对尾迹速度的分解以及总压损失发展的分析可知,尾迹在到达一倍弦长后,尾迹中的旋涡在与主流的掺混过程中逐渐减弱,叶栅出口损失仍然存在不均匀性,不均匀性的来源主要为轴向速度的亏损。

The effect of wake characteristics on the loss and aerodynamic stability of axial compressors is of vital importance.The flow field of the annular compressor cascade with IGV and OGV was measured,and the related wake losses were analyzed in detail based on the numerical simulations.The results show that steady simulations with SST turbulence model predict better according to the experimental results.Wake losses at the outlet of the annular compressor cascade are uneven in the radial direction.The total pressure loss increases from 20%to 50%span with peak loss observed at 30%span.The radial migration along the blade suction side of the low momentum flow in the boundary layer is identified as the main source of the total pressure loss.Based on the analysis of the wake velocity distribution and the development of the total pressure loss,the vortex intensity gradually reduces during the mixing with the main flow.After reaching one chord length downstream,the wake losses are still uneven and its unevenness is mainly due to the deficit of the axial velocity.