高速轴配流中旋转径向小孔流量系数的实验研究

Experimental Study on Flow Coefficient of the Rotating Radial Small Orifice Used in High Speed Shaft-type Commutation

针对高转速轴配流中旋转径向小孔出流流量系数开展了实验研究。研究中涉及到两种流动方向,即自旋转缸体中心流过径向小孔向外离心运动称为正向流动,反之则为反向流动。结果表明:旋转小孔出流流量系数同时显著地受离心力和科氏力的影响;因离心力的赋能作用,正向流动时流量系数随转速的增加而变大,反向流动时离心力对小孔内流动有抑制作用,使流量系数随转速的增加而变小;两个方向的科氏力综合效果使正向流动流量系数随出流雷诺数增加而变小,反向流动流量系数随出流雷诺数的增加而变大;当出流雷诺数足够大时,两种流动方向、不同孔型的流量系数各自都有一个稳定值;各种孔型的正向流动流量系数稳定值分布均在0.65~0.80范围内。

In view of the rotating working condition of radial small orifices used in shaft-type commutation of high speed axial piston pump,the experimental study on flow coefficients of flow passing through small orifices was conducted.The two flow directions involved in this study,namely,the flow from the axis-center of the rotating cylinder block outward through the orifice is positive flow,and vice versa is reverse flow.The results show that the centrifugal force and Coriolis force have significant effects on the flow in rotating small orifice,the centrifugal force exerted on the fluid has the effect of giving energy to the fluid in the positive flow,and the flow coefficients increase with the increase of rotating speed.In reverse flow,the centrifugal force exerted on the fluid in small orifice holds the flow,and the flow coefficients decrease with the increase of rotating speed.With the increase of the average discharge velocity in orifices,the overall effect of the Coriolis forces in both directions is to makes the flow coefficient of positive flow decrease,on the contrary,the flow coefficient of reverse flow increase.When the discharge Reynolds number is large enough,regardless of forward or reverse flow,the flow coefficients of different orifices types have respectively the stable value.The stable values of the flow coefficient of various orifices in positive flow are within the range of 0.65~0.80.