多级轴流压气机模化设计中尺寸缩放对气动性能影响的数值研究

为了研究几何尺寸模化缩放及叶尖间隙对多级轴流压气机气动性能及内部流动的影响，采用Numeca程序对17级轴流压气机开展了数值计算。结果表明：在80%及100%等高转速条件下压气机效率随着模化比例增大而增大，而在50%转速下模化缩放对压气机效率的影响较小。相对于原型压气机，模化放大时，压气机前8级单级压比均有所降低，而后8级压比均提高；模化缩小时，压气机的变化规律则相反。随着压气机几何尺寸的增大，静叶叶根和叶尖区域的总压恢复系数显著提高。同时，叶片叶尖泄漏流区域的熵增减少，从而使各级效率均有所提升。缩放模化中，随着叶尖间隙的增大，泄漏流增多，恶化了动叶叶尖附近的流动分离，降低了动叶后50%弦长区域的相对马赫数，同时扩大了静叶上端壁的流动分离，使压气机效率降低。

Numerical Study of the Effects of Size Scaling on Aerodynamic Performance in Multi-stage Axial Compressor Modeling Process

In order to investigate the effect of geometric modeling scaling and blade tip clearance on the aerodynamic performance and internal flow of the multi stage axial compressor,the numerical simulation based on the Numeca software was carried out for a 17 stage axial compressor in this study.The results show that as the scaling factor enlarges,the compressor efficiency increases under the conditions of 80% and 100% high rotating speed,while scaling factor has little effect on the compressor efficiency at the 50% speed.Compared with the prototype compressor,with the increase of the scaling amplitude,the single stage pressure ratio of the first 8 stages of the compressor is reduced,while that of the last 8 stages is all increased.With the reduction of the scaling amplitude,the change rule of the compressor is the opposite.As the geometric size of the compressor increases,the total pressure recovery coefficients of nozzle in the region near the hub and shroud increase significantly.At the same time,the entropy increase in the tip leakage flow area is reduced,so that each stage efficiency is improved.In the scaling process,as the blade tip clearance increases,the leakage flow increases,which worsens the flow separation near the blade tip,reduces the relative Mach number in the last 50% chord length region of the blade,and enlarges the flow separation in the region near the shroud of nozzle.The flow field characteristic will reduce the efficiency of the compressor.