摘要：采用计算流体动力学对叶轮式介质搅拌磨中的单相流湍流流场进行数值模拟, 分析不同转速下的流体速度、速度梯度、剪切力、湍流强度、湍动能输运等流场特性, 并对该搅拌磨磨腔内单相流 (水) 的流体速度进行实测。结果表明, 磨腔中的流体能量不断分散并重新分配, 产生随机分布的涡量, 流场能量主要集中在靠近叶轮搅拌器及腔筒内壁的区域内, 为有效研磨区;在一定范围内增大搅拌器转速, 流体速度及速度梯度增大, 流体之间剪切力增大, 研磨效果改善;黏度越小的湍流场, 湍流强度越高, 湍动能在传输过程中耗散越小, 能量利用效率越高;实测所得的流体速度变化情况与模拟结果相似, 两者的平均速度值相差较小, 表明模拟方法可行。

关键词：介质搅拌磨;数值模拟;单相流;速度梯度;能量

Abstract：The numerical simulation of single-phase turbulent flow behaviors such as velocity magnitude, velocity gradients, shear stress, turbulence intensity and turbulent transmission in an impeller stirred media mill at different shaft speeds was carried out by computational fluid dynamics. The fluid velocities of single-phase flow (water) in stirred mill grinding chamber were measured. The results indicate that the flow between the rotor discs relates to whirlpool and randomness due to the enhanced flow dispersion. The local energy dissipation is non-uniform because the energy dissipation occurs in a small zone around the discs and the wall, where the effective grinding occurs. The fluid shear stress increases linearly with velocity gradient of the flow. In a certain range, the flow velocity and the gradient both increase while increasing the shaft speed. The fluid velocities measured by Pitot tube are consistent to the simulated results. The difference between the simulated and experimental data is slight enough to show that the method could be used for simulation purpose.

Keywords：stirred media mill; numerical simulation; single-phase flow; velocity gradient; energy