水泵试验台汽蚀筒内部流场数值模拟

根据某多功能试验台闭式试验装置中参数测量范围的要求设计了一个汽蚀筒.以叶片角为-2,°型号为JM—211的混流泵为例,在其设计工况点Q=2200 m3/h下,采用雷诺平均N-S方程和标准k-ε紊流模型结合隐式修正SIMPLEC算法,运用FLUENT软件对此汽蚀筒进行了内部流场数值计算,并与试验值进行了对比分析.数值计算得到了汽蚀筒内部的速度矢量图、两层稳流栅（整流器）附近横截面的压力分布图,以及出口速度、压力分布图.分析结果表明,两层稳流栅后流速稳定,压力分布较为均匀,压差减小为250 Pa;泵进口压力试验值与计算所得的汽蚀筒出口压力值非常接近,压力预测误差仅为1.79%.因此,该汽蚀筒进出口和稳流栅的设计达到了试验所要求的泵进口压力且压力稳定.

Numerical simulation of flow in cavitation-tank of pump test-bed

A cavitation tank was designed based on the range of measuring parameters for a multi-functional test-bed. As regard to the JM--211 mixing-flow pump with- 2° blade angle, the cavitation-tank was simulated at the design point Q = 2 200 m^3/h by using the software FLUENT. The Reynolds Average N - S Equations, standard k - ε turbulence model and SIMPLEC algorithm were adopted. The distributions of velocity and pressure in the cavitation-tank, the rectifiers and the exit were analyzed. The calculation results were compared with those from experiments. The calculated results indicate that the distributions of velocity and pressure after the rectifiers are well-proportioned, and the decreased pressure difference was 250 Pa. The pressures of the pump inlet and outlet of the cavitation-tank were close, and the error of predicted pressure was merely 1.79%. The design of inlet and rectifiers of the cavitation-tank can achieve the required steady pressure at the pump inlet.