基于格子玻尔兹曼方法的液滴撞击移动液膜过程模拟  

Simulation of a droplet impacting on a moving liquid film with lattice Boltzmann method

作　　者：袁浩 黄宏宝 郭平措 何小泷[2] YUAN Hao;HUANG Hongbao;GUO Pingcuo;HE Xiaolong(Chongqing Southwest Research Institute for Water Transport Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China;Qinghai Water Resources Hydropower Survey and Design Institute,Xining 810001,China)

机构地区：[1]重庆交通大学重庆西南水运工程科学研究所,重庆400074 [2]四川大学水力学及山区河流开发保护国家重点实验室,四川成都610065 [3]青海省水利水电勘测设计研究院,青海西宁810001

出　　处：《水利水电科技进展》2021年第2期57-62,69,共7页Advances in Science and Technology of Water Resources

基　　金：国家重点研发计划(2016YFC0402006,2016YFC0401906);国家自然科学基金(51979183)。

摘　　要：采用可调节表面张力的大密度比格子玻尔兹曼伪势模型模拟了液滴撞击移动液膜的过程,并进一步分析了雷诺数、韦伯数和初始液膜运动速度对液冠演化的影响。结果表明:初始液膜运动速度会增大上游液冠处撞击后液膜运动速度不连续性,促进上游液冠变形,同时减小了下游液冠处撞击后液膜运动速度不连续性,对下游液冠演化具有抑制作用;上游液冠高度随雷诺数增大而增大,但不随韦伯数的变化发生改变,而下游液冠高度则随着雷诺数和韦伯数的增大而减小,但雷诺数和韦伯数均不影响到液冠半径的演化;随着初始液膜运动速度增大,上、下游液冠高度减小,但液冠半径增大。格子玻尔兹曼伪势模型模拟结果与试验结果和理论分析一致,证明格子玻尔兹曼伪势模型可以有效模拟复杂液膜条件下液滴撞击液膜过程。The pseudo-potential lattice Boltzmann method(LBM)with a tunable surface tension source term was applied to study a droplet impacting on a moving thin film.The effects of Reynolds number,Weber number and liquid film velocity on the evolution process of the liquid crown were analyzed.The results show that the initial liquid film velocity aggravates the kinematic discontinuity at the upstream liquid crown after impacting,leading to a dramatic deformation of the upstream liquid crown.However,the kinematic discontinuity in the liquid film at the downstream liquid crown is reduced,which can suppress the evolution of the downstream liquid crown.The upstream crown height increases with the increase of Reynolds number,but does not change with Weber number.The downstream crown height decreases with the increase of both Reynolds number and Weber number but the evolution process of the crown radius is not affected.Furthermore,with the increase of the initial liquid film velocity,both the upstream and downstream crown heights decrease,but the radius of the crown increases.The simulation results of LBM agree well with the experimental results and theoretical analysis,which proves that the pseudo-potential LBM is a robust and effective tool to simulate the process of a droplet impacting on a liquid film under complex conditions.

关 键 词：液滴 移动液膜 格子玻尔兹曼方法 液冠演化 雷诺数 韦伯数 

分 类 号：TV131.2[水利工程—水力学及河流动力学]