RSI现象的不稳定流动模拟

Rotator-stator interaction induced unsteady-flow simulation

随着水力机械单机容量和尺寸的增加 ,人们对其运行稳定性和振动问题日益重视 ,这就使水力机械内部不稳定流场计算显得十分必要。该文以水泵水轮机为对象 ,应用先进的“滑移网格技术”,采用 PISO(pressure- implicit withsplitting of operators)方法计算了包含涡壳、固定导叶、活动导叶及叶轮在内的过流通道内由于动静干涉 (rotor- statorinteraction,RSI)现象引起的不稳定流场 ;对计算结果进行FFT (fast Fourier transform )变换 ,获得了记录点的压力脉动频率 ,计算结果与实测结果吻合很好 ;

The oscillations in hydraulic machines are becoming more and more important with increasing of unit power and size. The oscillation must be analyzed by investigating the unsteady flow field in the hydraulic machine. This paper numerically simulates the unsteady flow field in a pumpturbine caused by RSI (rotorstator interaction). The calculation domain includes the spiral case, the stay vane, the guide vane and the runner. The PISO (pressureimplicit with splitting of operators) method was used for the pressure velocity coupling, RNG based the kε model was used for the turbulence and the sliding mesh was used to deal with relative movement of the two parts (runner and guide vane). The results were analyzed by FFT (fast Fourier transform) to determine the pressure oscillation frequencies at different points. The calculated results agree well with the measured results which show that the pressure oscillation frequency is closely related to the blade passing frequency.