CFD-PBM框架下旋流式微泡发生器气泡动力学行为  

Bubble dynamics in micro-bubble generator with swirl flow based on CFD-PBM framework

作　　者：邢继远 XING Jiyuan(Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海高等研究院,上海201210 [2]中国科学院大学,北京100049

出　　处：《化学工程》2024年第3期59-65,共7页Chemical Engineering(China)

摘　　要：为探究旋流式微泡发生器气泡直径变化规律以及气泡动力学行为,采用欧拉-欧拉非均质气液二相模型求解流动参数,并耦合PBM(群体平衡模型)求解直径在1—1000μm内的14个直径气泡数密度变化,利用Luo破碎-Liao合并组合模型对旋流式微泡发生器内部的气泡破碎合并行为进行分析。模拟计算结果与实验相近,说明CFD-PBM可以用来求解旋流式微泡发生器内部的气泡直径变化。由此可知,模拟条件下,气泡破碎频率对于液体流速变化更加敏感,气泡合并频率对于当地含气率变化更为敏感;气相主要分布在旋流式微泡发生器的中轴线附近处,并且沿着中轴线可见细长分布类似龙卷风形状的大气泡区;液体流量增加及出口直径的减小均会促进出口气泡直径的减小;气泡直径对于入口气体流量的变化并不敏感,并且这种影响关系还受到出口直径的影响。In order to investigate the variation of bubble diameter and the dynamics behavior of bubble inside the SFMBG(micro-bubble generator with swirl flow),the Euler-Euler inhomogeneous gas-liquid two-phase model was used to get flow parameters,and by coupling population balance model to compute the number density of the 14 bubbles with the diameter from 1μm to 1000μm.Moreover,the bubble breakup and coalescence behavior inside the SFMBG was analyzed based on the Luo-breakup and Liao-coalescence combination model.As a result,the data of simulation is close to that of experiment,indicating that CFD-PBM(computational fluid dynamics population balance model)can be used to get knowledge of the variation of bubble diameter in SFMBG.Under the theoretical condition,the bubble breakup frequency is more sensitive to the liquid velocity change,while bubble coalescence frequency is more sensitive to the variation of local gas content.Besides,the gas phase is mainly distributed in the vicinity of the central axis of the SFMBG,and a large bubble area with tornado shape can be seen along the central axis;Most importantly,increasing liquid flow rate and decreasing outlet diameter can promote the reduction of the outlet bubble diameter.However,the effect of changing inlet gas flow on outlet bubble diameter is not sensitive,and this relationship is also influenced by the outlet diameter.

关 键 词：旋流式微泡发生器 二相流 计算流体力学 数值模拟 群体平衡模型 

分 类 号：TQ021.1[化学工程]