基于FLUENT的离心泵内流特性数值模拟研究

Numerical Simulation of Centrifugal Pump Internal Flow Characteristics Based on FLUENT

离心泵作为高速旋转机械,其内部复杂的流动形态越来越受关注。该文依据某工程数据,基于FLUENT软件建立离心泵三维流体域数值仿真模型,分别对离心泵在0.2Q d(Q d为该离心泵设计流量)、0.4Q d、0.6Q d、0.8Q d、1.0Q d、1.2Q d 6个不同流量工况下的内部流动特性进行模拟计算,并将计算所得流量-扬程和流量-效率曲线与真机试验结果进行对比,计算结果与试验结果最大误差为4.71%,从而证实了数值仿真结果的可靠性。通过对压力和速度分布分析可知:离心泵内部静压和流速随流量增加而降低,叶片前缘存在负压区,易引发汽蚀、振动、噪声等不良结果。相较小流量工况,设计工况下泵内速度分布更加均匀。对泵内流态进行多角度分析,对离心泵的结构优化设计有一定的借鉴意义,可为类似工程提供参考。

Centrifugal pump as a high-speed rotating machinery,its internal complex flow pattern has attracted more and more attention.In this paper,a three-dimensional fluid domain numerical simulation model of centrifugal pump was established based on FLUENT software based on an engineering data,and the internal flow characteristics of the centrifugal pump were simulated under six different flow conditions of 0.2 Q d(Q d is the designed flow rate of the centrifugal pump),0.4 Q d,0.6Q d,0.8Q d,1.0Q d and 1.2Q d,respectively.The calculated flow-head and flow-efficiency curves are compared with the real machine test results.The maximum error of the two curves is 4.71%,which confirms the reliability of the numerical simulation results.Through the analysis of the pressure and velocity distribution,it can be seen that the internal static pressure and velocity of the centrifugal pump decrease with the increase of the flow rate,and there is a negative pressure area in the leading edge of the blade,which is easy to cause cavitation,vibration,noise and other adverse results.Compared with the low flow condition,the speed distribution in the design condition is more uniform.The multi-angle analysis of the flow pattern in the pump has certain reference significance for the structural optimization design of the centrifugal pump,and provides reference for similar analysis.