自吸泵自吸过程气液两相流数值模拟分析

摘要

自吸泵的自吸过程是一个很复杂的气液两相混合流动与分离过程.本文利用非稳态数值模拟方法模拟自吸泵自吸过程,初始条件为进水管及出水管含有部分空气,然后估算自吸时间.模拟结果表明:泵吸气和排气主要集中在自吸初期,期间叶轮入口和泵出口气含率最高分别可达62.4％和45.3％;叶轮入口气含率变化较泵出口气含率变化剧烈;此外,叶轮与导叶间隙对自吸性能有影响,间隙与自吸时间呈负相关变化,说明较大的间隙有利于泵的自吸.%The self-priming process of self-priming pump was a very complicated gas-liquid mixed flow and separation process.In this article,a unsteady numerical simulation was applied to simulated the selfpriming process of self-priming pump,with the initial condition was that the inlet and outlet pipe filled with air,and then self-priming time was estimated;The simulation results showed that gas inhaled into and discharged of the pump were mainly concentrated in the early stage of the self-priming process,the air void fraction reached up to 62.4％ and 45.3％,respectively at the impeller inlet and the pump outlet in the initial stage;The change of air void fraction in the impeller inlet was more drastic than that of the pump outlet;In addition,self-priming performance was affected by the gap between impeller and guide vane,and the data showed a negative correlation between gap and self-priming time,which revealed the lager gap was beneficial to self-priming of the pump.