气浮接触区气泡聚并行为的数值模拟

发布时间：2018-02-25 09:21

本文关键词： 气浮气泡聚并速度梯度相群平衡模型数值模拟计算流体力学　出处：《化工学报》2016年06期 　论文类型：期刊论文

【摘要】：在气浮接触区内,聚并会导致气泡直径增大,对分离效果产生影响。采用相群平衡模型对接触区气泡聚并行为进行数值模拟,研究了气泡聚并发生的原因及来液流量、回流流量对气泡聚并的影响。首先分别应用Schiller-Naumann、Grace和Tomiyama 3种曳力系数模型进行模拟,所得气泡直径均与实验值吻合,无明显差异,选定Schiller-Naumann曳力系数模型对气浮中两相流动进行模拟。通过对模拟结果进行分析,表明回流入口周围上下行流过渡区域存在较大速度梯度,是导致气泡聚并的关键因素。最后研究了来液流量和回流流量对接触区气泡尺寸的影响,接触区上部气泡直径随回流流量增大而明显增大,原因在于增大回流流量使得过渡区域速度梯度升高,气泡聚并频率提高;而来液流量对气泡尺寸基本无影响。
[Abstract]:In the floatation contact zone, coalescence will lead to bubble diameter increases, impact on the separation effect. The population balance model of the contact zone bubble coalescence was simulated, the reason of bubble coalescence occurs and fluid flow, back flow effect on bubble coalescence. Firstly, using Schiller-Naumann, Grace Tomiyama and 3 kinds of drag coefficient model was simulated, the bubble diameter are in agreement with experiment, no significant difference, Schiller-Naumann model of the air drag coefficient is selected in two-phase flow simulation. By analyzing the simulation result showed that the return on the downstream transition region around the entrance there is a big velocity gradient is the key factor leading to the bubble coalescence the final study. To influence the fluid flow and reflux flow on the contact zone of bubble size, bubble diameter upper contact zone with reflux flow increases clearly increased The reason is that the increasing flow rate increases the velocity gradient in the transition region, and the bubbles gather and increase the frequency, but the flow rate has no effect on the size of the bubble.

【作者单位】：中国石油大学(华东)重质油国家重点实验室;
【基金】：中央高校基本科研业务费专项资金项目(14CX06097A)~~
【分类号】：O35

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