固相体积分数对螺旋离心泵内流场的影响

Influence of Solid Volume Fraction on Inner Flow Field of a Screw Centrifugal Pump

以某螺旋离心泵为研究对象,分析了在介质为固液两相时,初始固相体积分数沿内流场的分布变化规律和对螺旋离心泵内流场的影响.选用固液两相含沙水为介质,应用计算流体动力学软件Fluent,建立相对坐标系下的时均连续方程及Navier-Stocks方程进行数值模拟,得到螺旋离心泵内流场压力分布以及颗粒浓度分布.结果表明:螺旋离心泵内压力分布受介质固相体积分数的影响明显,而且影响到泵的扬程,体积分数过大会造成螺旋离心泵性能下降;体积分数过小,不能使螺旋离心泵在输送两相流时优势充分发挥,存在最优体积分数50%,使该泵在额定流量下扬程最高.

With a screw centrifugal pump as the object of study,choosing the solid-liquid,two-phase flow of sand and water as the medium,this paper researches the distribution of the initial solid volume fraction along the inner flow field and the influence of the fraction on the inner flow field in a screw centrifugal pump. We established the time-averaged continuous equation and N-S equation under relative coordinates on the basis of th Fluent software,and obtained the distribution of pressure and particle concentration of the inner flow field in a screw centrifugal pump. The results indicate that the pressure distribution in a pump is obviously influenced by the solid volume fraction of the medium,and the lift of a pump is also in- fluenced;a too large volume fraction leads to the pump performance degradation,and the pump cannot convey the two-phase flow when the volume fraction too low.