考虑压气机动静干涉效应的非设计工况性能数值模拟

Numerical simulations of compressor off-design performances with rotor-stator interaction

关键词:  非定常流动  非设计工况  数值仿真  轴流压气机

Key words:  Unsteady flow  Off-design condition  Numerical simulation  Axial compressor

摘要:

应用数值模拟方法研究了非设计工况下轴流压气机动静叶排相互干涉的非定常流动,利用高分辨率格式求解准三维雷诺平均N-S方程,非定常流场计算采用了双时间步法与LU-SGS隐式解法耦合的方法。计算给出了在100%,90%和80%设计转速下等转速特性的定常和非定常流的计算结果,两者的比较表明,定常流计算得到的效率低于非定常的结果,边界点附近定常流的增压比高于非定常的结果。不稳定边界附近的非定常流计算结果表明,利用叶片表面压力变化是否具有周期性作为等转速线上边界点的判别准则更为合理。

Abstract:

The unsteady flow of rotor/stator interaction at off-design condition in axial compressor was investigated numerically.Quasi three-dimensional unsteady Navier-Stokes equations were solved with high-resolution scheme.Dual time-stepping approach in conjunction with LU-SGS implicit method was used to calculate the unsteady flow.The steady and unsteady performances at 100%,90% and 80% design rotating speed respectively were presented.The computation showed that adiabatic efficiency values for steady flow is lower than that of unsteady flow.However,the calculated total-to-total pressure ratio is greater than the unsteady results.The numerical analysis showed that the stall margin can be determined by the unsteady computed results.The state is stable if unsteady surface pressure varies periodically with time,while it is unstable when the variations are not periodic.