双叶片排污泵固液两相流的数值模拟

A Numerical Simulation of Solid-liquid Two-phase Flow in Two-blade Sewage Pumps

为了研究双叶片排污泵叶轮、蜗壳的磨损规律,以WQ8-20-1.5的双叶片泵为研究对象,采用RNGk-ε湍流模型、SIMPLEC算法和Mixture两相流模型,数值模拟了设计工况下固相体积分数为6%、15%、20%和粒径为0.06、0.12、0.18mm时的固液两相流场,分析了不同颗粒体积分数、不同颗粒直径对流动的影响。结果表明:在叶轮流场内,固相颗粒分布不均匀,颗粒主要集中在叶片工作面及其出口处的前后盖板处;蜗壳流道内,固相颗粒呈靠近壳体分布,固体颗粒大多集中在蜗壳第七断面至出口处;粒径越大,离析现象越明显,颗粒体积分数对固相离析作用较小;颗粒直径越大,扬程效率降低,但变化较小,颗粒体积分数增加,扬程效率降低,降低程度较大。过流壁面切应力随着颗粒粒径和体积浓度的增大而增加,体积分数对其变化更为明显。

The research model is two-blade sewage pump named WQ8-20-1.5. With RNG k-e turbulence model, SIMPLE（; algorithm and mixture two-phase flow model, the solid field is simulated by the solid fraction of 6%,15%, 20% and particle size of 0. 06, 0. 12, 0.18 mm under design conditions. The results show that the particles of the solid phase are distributed unevenly in the impel- ler flow field. The particles are mainly concentrated in the blade pressure surface and at the front and rear cover of its export. With the increase in solid particles, the solid volume concentration of the volute flow channel increases. The particle size distribution of the solid phase of the volute flow channel within is close to the shell side of the trend, the solid particles are mostly concentrated in the seven section to the exit. The effect of increase in the particle diameter on the solid phase segregation is more significant, the particle volume fraction of solid phase segregation effect is small. The larger the particle diameter, the lower the head efficiency is, but the change is small. The particle volume fraction increases, the lower the head efficiency is.