单级跨声速压气机旋转失速模拟方法

Numerical Simulation of the Rotating Stall Feature on a Single Stage Transonic Compressor

为了研究多排跨声轴流压气机旋转失速先兆的表现形式与失速演化规律,基于自主研发的CFD软件ASPAC,通过发展动态重叠网格技术,流量出口边界条件以及节流阀边界条件,对单级跨声速压气机NASA Stage 35由近失速状态到完全失速状态的过程进行了模拟.结果表明,发展的数值模拟方法能准确地模拟多排压气机的旋转失速发展过程;均匀进气条件下,随着NASA Stage 35向失速状态逼近,某些动叶压力面前缘出现了叶顶间隙流溢流现象,促使压气机进入旋转失速状态;在失速先兆阶段,周向非均匀流动开始出现并沿压气机周向传播;当完全失速时,失速团充分发展并连续地沿周向旋转,结构几乎不随时间变化.

To study the characteristics of stall inception and stall development in multi-row transonic axial compressor,taking NASA Stage 35 as an example,the development from near stall to fully developed stall was simulated.The simulation was conducted based on the in-house code ASPAC.The dynamic overlapped grid technique,mass flow boundary at the outlet,throttle valve boundary condition were used.The simulation result indicates that:the developed simulation technique can predict the development process of rotating stall correctly.Under the condition of uniform inlet flow,as the flow approaches to stall condition,the blade tip leakage occurs on the leading edge of pressure surface for some rotors,which leads to the rotating stall of the compressor.Under the condition of stall inception,circumferential non-uniform flow occurs and propagates circumferentially.When the rotating stall is fully developed,the adverse flow occurs on the pressure surface of stator and is mainly adjacent to the stall cells in the rotor,meanwhile the flow structure in the stall region nearly does not change with time.