Abstract An extensive set of experiments was carried out to examine the effects of impeller types, impeller locations (submergence), solid volume fraction, and baffle configuration on the drawdown efficiency. Flow simulations in a turbulent regime were also performed to investigate the flow patterns, spatial homogeneity (using the mean age distribution), and particle drawdown mechanisms (using a particle level simulation with the discrete phase model). A combination of two casting impellers (a helical impeller near the top and a radial one near the bottom) with two half-baffles was determined to be the optimal configuration for complete drawdown with enhanced particle distribution, while avoiding air entrainment and lowering the impeller speed. Hydrodynamic mechanisms leading to superior drawdown and dispersion performance of the optimal design are discussed with the formation of free surface swirling, turbulence strength, roles of half baffles and helical/radial impellers on the flow and particle motions.

中文翻译：

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金属基复合材料制造中轻颗粒的搅拌浇铸系统

摘要 进行了大量实验以检查叶轮类型、叶轮位置（浸没）、固体体积分数和挡板配置对压降效率的影响。还进行了湍流状态下的流动模拟，以研究流动模式、空间均匀性（使用平均年龄分布）和粒子下降机制（使用具有离散相模型的粒子级模拟）。两个铸造叶轮（靠近顶部的螺旋叶轮和靠近底部的径向叶轮）与两个半挡板的组合被确定为最佳配置，以增强颗粒分布，同时避免夹带空气并降低叶轮速度.