旋转盘反应器流场特性的PIV测试和CFD模拟

PIV measurement and CFD simulation of flow characteristic in a spinning disc reactor

通过PIV实验和CFD数值模拟研究了旋转盘表面的流动特性和变化规律。基于VOF多相流模型和Realizable k-ε湍流模型,CFD模拟结果与实验结果形成对比,考察了不同转速和流量条件下旋转盘表面的液膜厚度分布、停留时间和分布情况。结果表明:盘的中心区域受流速控制,流动方向更接近径向流动,边缘区域受转速控制,流动方向更接近圆周流动。液膜厚度随径向半径的增大先增大后减小,转速的增加导致边缘区膜厚减小。流速的增加导致中心区域的膜厚度减小和边缘区域的膜厚度增加。平均停留时间随转速和流速的增加而降低。停留时间分布表明,在实验条件下,液体流动更接近活塞流动。

The flow field and variation in a spinning disk reactor were investigated by particle image velocimetry(PIV)measurement and Computational Fluid Dynamics(CFD)simulation.CFD simulation was performed based on the volume of fluid(VOF)multiphase flow model and k-εrealizable turbulence model,the liquid film thickness distribution,residence time and distribution of the rotating disk surface were investigated under different rotating speeds and flow rates.The results show that the velocity at the center of the disk is controlled by the flow rate,resulting in a flow close to the radial flow;whereas the velocity at the periphery of the disc is controlled by the rotational speed,resulting in a flow close to the circumferential flow.The liquid film thickness increases at first and then decreases in the radial direction.Increasing the rotational speed could lead to a decrease of the liquid film thickness at the periphery;while increasing the flow rate leads to a decrease of the liquid film thickness at the central but an increase at the periphery.The average residence time decreases with the rotational speed and flow rate increasing.It shows that the liquid flow is like the plug-flow under the experimental conditions.