后置静叶周向弯曲对表面非定常压力脉动的影响

The influence of the circumferential skew on the unsteady pressure fluctuation of surfaces of rear stator blades

在目前的叶轮机械中,普遍存在着旋转动叶与后置静叶干涉产生的非定常流动现象。这种流动现象会导致静叶表面产生非定常性压力脉动。这种脉动可分为旋转动叶的速度亏损尾迹引起的叶片表面的周期性脉动和气流本身的湍流脉动及其他涡团导致的随机脉动两个方面。采用一工业用单级通风机,对其动静叶的干涉现象进行研究。通过在后置静叶表面沿弦长及叶高方向布置动态压力传感器的方法,研究静叶的周向弯曲(倾斜)角度对静叶表面的非定常力的影响。研究结果表明:采用周向弯曲静叶会改变动叶尾迹所引起的后置静叶周期性脉动的幅值在静叶表面的分布特点,静叶顶部压力脉动的幅值与原始径向静叶相比能够有效地降低,同时与中部的压力幅值相比有一定提高,但整体呈现下降趋势;另一方面,静叶表面随机性的压力脉动强度受周向弯曲的影响较小。

In the turbomachinery, there is unsteady flow field caused by the interaction of ro tating rotor and rear stator. The unsteady flow results in the unsteady pressure fluctuation acting on the rear stator surface. This unsteady pressure includes periodic pressure fluctuation caused by the interaction of periodic rotor wake and rear stator and pressure fluctuation caused by the tur bulence and other vortex movement in the flow field. In this paper, we have chosen the dynamic pressure sensors to measure the pressure fluctuation on the surface of the stator vane along the direction of the chord length and blade height in an industrial sole stage fan. The research focused on the relation of circumferential skew angle and the amplitude of the pressure fluctuation. The results show that the circumferential skew stator can effectively reduce the amplitude of periodic pressure fluctuation of the surface of the stator blades at the tip while increase the amplitude at the mid-span. This can decrease the amplitude of the periodic pressure fluctuation on the whole blade. The results also show that the circumferential skew has less effect on the amplitude of the broadband frequency pressure fluctuation.