多喷嘴射流泵流场的数值模拟与PIV测量

为研究多喷嘴射流泵性能和内部流场特征,设计了不同结构的多喷嘴射流泵试验模型.采用k-ε湍流模型和壁面函数法对不同参数下的多喷嘴射流泵进行了数值模拟,模拟结果表明,喷嘴数和喷嘴角度及喉嘴距对射流泵工作性能影响较大;在吸入室及喉管入口处湍动能较大.利用PIV系统对不同结构射流泵内部流场进行了三维测量,获得了射流泵对称面流场的速度矢量和湍动能等值线图.试验结果表明,其速度梯度衰减得愈快,工作流体和被吸流体混合距离越短.验证了多喷嘴射流泵可缩短喉管长度.测量结果证明数值模拟的正确性,为多喷嘴射流泵理论研究和合理设计提供了理论依据.

PIV measurement and numerical simulation of flow field in multi-nozzle jet pump

In order to study the performance and flow characteristic of multi-nozzle jet pump, the multinozzle jet pumps with different structures are designed. The pumps with different structural parameters are simulated numerically using k -ε model and wall functions. The results showed that the number of nozzles, the nozzle angle and the nozzle-to-throat clearance have a great influence on the performance of jet pump, and the turbulent kinetic energy is greater in suction chamber and in inlet of throat. PIV is used to measure the internal flow field of jet pumps with different structures. Velocity vectors and turbulent kinetic energy contours on the symmetry plate of the jet pump are obtained. The results show that the faster the velocity gradient decays, the shorter mixing distances of operating fluid and the drawn liquid are. The multi-nozzle jet pump could shorten the length of throat pipe. The measurement results agree with the numerical simulation.