构成轴流压气机出口不稳定的主要影响因素

Unsteady effects on isolated rotor exit of an axial flow compressor

关键词:  轴流式压气机  转子叶片  非定常流  纳维尔斯托克斯方程

Key words:  Axial flow compressor  Rotor blade  Unsteady flow  Navier-Stokes equation

摘要:

为探讨构成转子出口不稳定性的主要影响因素 ,借助三维N S方程数值求解轴流压气机孤立转子流场 ,计算了转子出口沿主流方向的不稳定参数并与实验结果加以对比 ,两者吻合较好。计算结果分析表明 :转子下游的不稳定性主要由紊流脉动动能和尾迹亏损构成 ,且前者占主要成分。采用双方程紊流模型的三维N S方程求解结果 ,可以有效地模拟转子出口不稳定参数沿径向的分布 ,对进一步深入探索转子出口流动的非定常效应具有重要的理论意义和工程实用价值。

Abstract:

An isolated axial flow compressor rotor was investigated computationally by Navier-Stokes solver The main contributors which cause some unsteadiness downstream of the rotor were studied in detail based on the calculated 3-D flow field The total unsteadiness in the mean flow direction was calculated and compred with experimental data The comparison shows a good agreement for total unsteadiness prediction The calculation results also show that both the turbulence kinetic energy and the wake velocity deficit make important contributions to the total unsteadiness downstream of the rotor Higher turbulence kinetic energy was produced by tip leakage flow, passage vortex and hub corner stall, which resulted in that much unsteadiness exists in rotor tip region near the hub and inside the blade wake This method for evaluating total unsteadiness can be useful tools to investigate the effects of unsteady-flow mechanics