喷嘴偏心距对射流泵性能影响的数值模拟

Numerical simulation of influence of eccentricity of nozzle on jet pump performance

对射流泵内部流动进行了数值模拟,计算了射流泵在不同喷嘴偏心距下的性能参数,分析了射流泵喷嘴轴线偏离泵体轴线的偏心距对其性能和流场的影响.结果表明:喷嘴偏心距对射流泵大流量比工况的性能有较大的影响,而对小流量比工况影响较小,可忽略不计;随着偏心距的增加,射流泵效率最高点下降并向流量比小的方向移动.在工程应用中,射流泵同轴度精度要求可以定为12级以上.

The effect of eccentricity of nozzle,which is the offset between axes of nozzle and pump body,on the flow field and performance of jet pump are examined numerically.The performance parameters of jet pump with different eccentricities of nozzle have been calculated.It is revealed that the eccentricity of nozzle has a great influence on the performance when jet pump works in operating mode of big flow ratio,but nearly none effect in small flow ratio.The maximum efficiency and the corresponding flow ratio decrease as the eccentricity increases.In view of engineering application,it is reliable and economical when the degree of proper alignment accuracy for jet pump achieves 12 and above.