基于Mixture多相流模型计算双流道泵全流道内固液两相湍流

    Simulation of solid-liquid two-phase turbulent flow in double-channel pump based on Mixture model

    • 摘要: 采用Mixture多相流模型、扩展的标准k-ε湍流模型与SIMPLEC算法, 应用计算流体力学软件Fluent对双流道泵全流道内的固液两相湍流进行了数值模拟,并将计算结果与清水单相流数值模拟及泵外特性性能试验进行了对比,揭示了不同粒径及颗粒体积浓度条件下双流道泵全流道内的固液两相流动规律。研究结果表明:在叶轮流道内,固相体积浓度分布极不均匀,颗粒主要集中于叶轮出口处的工作面和后盖板上,但是随着颗粒浓度和粒径的减小,会出现颗粒向背面迁移的趋势;在蜗壳流道内,颗粒主要集中于靠近蜗壳出口侧的流道区域,颗粒运动轨迹紊乱,少部分颗粒脱离叶轮后能直接从蜗壳出口流出,大部分颗粒撞击蜗壳壁面,留在蜗壳内转动数圈才能流出;颗粒浓度变化对固相的离析作用影响相对较小;粒径变化对固相的离析作用影响较大,粒径越大,颗粒撞击点愈加集中于叶轮工作面,固相的离析作用越明显;相同体积流量下,泵进出口总压差随颗粒浓度和粒径的增加而减小。

       

      Abstract: To further study the solid-liquid two-phase flow mechanism in double-channel pump, three-dimensional simulation was performed for the solid-liquid two-phase turbulent flow in double-channel pump by using Fluent software with mixture model, extended SIMPLEC algorithm and standard k-ε turbulence model. The calculation results were compared with the computational results of single-phase simulation, as well as the experimental data. It is concluded that: in channels of impeller, the volume fraction contour is extremely nonuniform, solid particles mainly accumulate on pressure surface of impeller, but tend towards suction side at the condition of low sandy volume fraction and small particle diameter; in channels of volute, solid particles are mainly concentrated in the channel near the exit of volute, few solid particles can directly flow out of the volute, and a large number of solid particles collide with volute wall and exit the volute after circling around the volute for several times; sandy volume fraction has less influence on distribution of volume fraction compared to solid particle diameter; inlet and outlet total pressure difference declines with the increase of sandy volume fraction or particle diameter.

       

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