动态混合器内流动和混合特性的CFD模拟

首先建立了动态混合器的三维实体模型，然后利用动态方腔拖曳流的粒子图像测速（PIV）流场实验检验了模拟方法的可靠性。在此基础上对动态混合器进行了计算流体力学（CFD）模拟，研究了进料量和操作转速对混合器内流动和混合特性的影响规律。研究结果表明：动态混合器的高剪切速率主要集中在定转子交界处；动态混合器出口处的浓度分布标准差正比于质量流量，反比于转速。最后提出了一种评价动态混合器操作性能的新方法。
Abstract：Dynamic mixers have many advantages and a wide range of applications in the field of high viscosity polymer blending. In this paper, the 3D model of dynamic mixer is established firstly, and then the reliability of the simulation method is verified by flow field of the dynamic lid-driven cavity obtained by the particle image velocimetry (PIV) experiments. Based on the simulation method, the effects of feed rate and operating speed on the flow and mixing characteristics in the dynamic mixer were studied. Studies have shown that the high shear rate region of the dynamic mixer is mainly concentrated at the junction of the stator and rotor, and that the standard deviation of the concentration distribution at the outlet of the dynamic mixer is proportional to the mass flow rate and inversely proportional to the operating speed. Finally, a new method for evaluating the operating performance of a dynamic mixer is presented.