组合压气机性能和气动稳定性计算分析

采用全三维数值计算方法研究了某型组合压气机性能和气动稳定性,通过对比轴流压气机和离心压气机的特性和流场细节,发现两者的特性差别较大:轴流压气机效率较高,总压比较小;工作点位于峰值效率点左侧时随流量的减小,离心压气机总压比和效率略有降低,轴流压气机总压比的增加和效率的降低均非常明显;导致离心压气机效率偏低的主要原因是径向扩压器的总压恢复系数偏小;导致组合压气机失稳的主要原因是轴流第1级转子叶尖和第2-3级静子叶根的泄漏流造成的堵塞。

Numerical Simulation on Performance and Aerodynamic Stability of Axial-Centrifugal Compressor

Three- dimensional numerical simulation method was used to research performance and aerody- namic stability of an axial- centrifugal combined compressor. The difference of characteristics with axial and centrifugal compressor is significant. Axial compressor has higher efficiency and lower total pressure. When the operating point locates on the left of peak efficiency point and the mass flow reduced, both of the total pressure and efficiency will slightly decrease. The increase of total pressure and decrease of effi- ciency of axial flow compressor was obvious. Causing low efficiency of centrifugal compressor is the small recovery coefficient of radial diffuser. The main reason for instability is the blocking caused by tip leakage flow of the first stage rotor, and the second to fourth stator.