气液并流垂直液膜流动的数值模拟  

Numerical Simulation of Co-Current Gas-Liquid Vertical Liquid Film Flow

作　　者：许松林[1] 赵婵[1] 

机构地区：[1]天津大学化工学院,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2014年第12期1039-1046,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(20976118;21176170)

摘　　要：应用计算流体力学软件Fluent,采用VOF方法模拟了气液并流垂直液膜流动.将平均液膜厚度数据与文献数据对比,验证了模型的合理性.考察了气、液相雷诺数和壁面剪切力对液膜流型的影响,分析了不同截面液膜厚度随时间的变化情况,且比较了液膜波动与壁面剪切力的变化规律.模拟结果表明:液膜的流动形态在不同高度处主要有滴状流、层流、层流-湍流和波状湍流,可划分为入口段、发展段和稳定段3个区域;波形低谷值对应剪切力的高峰值,大振幅波的高峰值对应剪切力的低谷值,但由于液膜波动的随机性以及波的叠加,并不是所有的剪切力高峰都与液膜波谷相对应.The volume-of-fluid （VOF） method was employed to simulate the co-current gas-liquid two-phase flow in a vertical falling film tube by a computational fluid dynamics（CFD） code Fluent. To validate the simulation model, the average data of liquid film thickness were compared with the published experimental data. With the valid model, the influences of two-phase Reynolds number and wall shear stress on flow types of liquid film were investigated. The change of liquid film thickness profiles with time at different cross sections was analyzed. In addition, the rules of change in wavy liquid film and wall shear stress were compared. It is found that the liquid film flow pattern consist of the droplet, laminar flow, laminar-turbulent flow and wave turbulent flow at different heights. It can be divided into three regions including entry, developing and stable regions. The wave trough value of instantaneous liquid film thickness was synchronized with the peak value of wall shear stress, and the peak value of large amplitude wave was correspondent with the trough value of wall shear stress. However, the peak of wall shear stress was not always synchronized with the trough of liquid film due to the random fluctuations and superposition.

关 键 词：液膜 气液并流 波状流动 壁面剪切力 

分 类 号：TQ021.1[化学工程]