半开式离心泵叶顶间隙对泵性能稳定性的影响

Influence of tip clearance of semi-open centrifugal pump on performance stability

为提高火箭发动机涡轮泵性能稳定性,应用边界层理论进行了半开式离心泵叶顶间隙流动特性研究,利用边界层动量积分方程对叶顶间隙内边界层厚度进行求解,并开展了不同叶顶间隙泵性能试验及流场数值模拟研究。结果表明,当叶顶间隙值等于间隙内边界层厚度值时,间隙泄漏涡不再增强,可获得稳定的泵性能;当叶顶间隙过大,会使泵容积效率降低,导致泵性能急剧下降。该理论方法可作为设计过程确定半开式离心泵叶顶间隙的重要参考。

In order to improve the performance stability of liquid rocket engine turbopump, theflow characteristics of semi-open centrifugal pump tip clearance are studied by means of the boundarylayer theory. The thickness of the boundary layer in tip clearance is calculated with the boundary layermomentum integral equation. The pump performance test and numerical simulation study are carriedout with different tip clearances. The results show that, when the tip clearance is equal to thethickness of boundary layer, the tip clearance leakage vortex will no longer be enhanced and the pumpperformance is stable. The volumetric efficiency of the pump is low when the tip clearance is toolarge and the pump performance drops off precipitously. The theoretical method can be used as animportant reference to determine the semi-open certrifugal pump tip clearance.