黏弹性流体系统附壁液滴剪切变形及运动研究  

Numerical study on deformation and motion of a wall-attached droplet in linear shear flow with viscoelastic rheology

作　　者：王宁宁[1] 倪旺来 王东 刘海湖[1] WANG Ningning;NI Wanglai;WANG Dong;LIU Haihu(School of Energy and Power Engineering,Xi'an Jiaotong University,710049 Xi'an,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《应用力学学报》2025年第1期212-222,共11页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.12072257,12202344,51876170);陕西省自然科学基础研究计划项目(No.2022JQ-502);西安交通大学基本科研业务经费资助项目(No.xzy012021019)。

摘　　要：附壁液滴的变形和运移与残余油的微观驱油效率密切相关,鉴于聚合物驱替液及稠油均可表现出黏弹性流变性质,阐明两相流体黏度等物性条件对黏弹性流体系统附壁液滴行为的影响机制十分必要。采用黏弹性流体两相流格子玻尔兹曼方法,结合接触角几何公式处理润湿边界条件,开展了线性剪切流中Oldroyd-B黏弹性环境流体内牛顿液滴(N/V系统)及牛顿环境流体内Oldroyd-B黏弹性液滴(V/N系统)在两相流体黏度比m、黏弹性流体溶剂黏度比β影响下的稳态变形及运移规律研究。结果表明:N/V系统聚合物的拉伸在界面尖端外侧及前进接触线附近最为显著,形成弹性拉力促进铺展;随β降低(弹性增强),润湿面积增加,表面积减小;随m增加,润湿面积增加,表面积增大;N/V液滴移动速度在m<1.5时,随β降低而升高;但m≥1.5时,液滴所受总驱动力在β较小时因液滴高度显著降低而减小,导致其移动速度随β降低而减慢。V/N液滴内聚合物拉伸在后退接触线附近更强,抑制液滴铺展;m≤1时润湿面积受m及β影响不大;m>1时润湿面积随m增加、β升高而增大。V/N液滴表面积受m和β的影响与N/V液滴趋势相一致,且两系统内液滴移动速度均随m增加而减小,但V/N液滴在各m条件下始终在β较小时移动速度略高。The deformation and movement of wall-attached droplets are closely related to the microscale displacement efficiency of residual oil.Since both the displacing liquid in polymer flooding and the heavy oil can exhibit viscoelasticity,it is necessary to clarify the influence of the viscosity-related fluid properties on the behavior of wall-attached droplets in viscoelastic fluid systems.The two-phase viscoelastic lattice Boltzmann method,combined with the geometric wetting boundary condition,is used to investigate the steady-state deformation and motion of a droplet under shear flow,where either the matrix phase(N/V system)or the droplet phase(V/N system)is the Oldroyd-B viscoelastic fluid while the other phase is the Newtonian fluid.The effects of the two-phase viscosity ratio m and the solvent viscosity ratio β of the viscoelastic fluid are studied.Results show that the stretching of polymer molecules in the N/V system is the most pronounced outside the droplet tip and near the advancing contact lines,which acts to promote droplet spreading.The wetting area of the Newtonian droplet in the Oldroyd-B matrix is increased by either decreasing β(increasing elasticity)or increasing m.The droplet surface area in the N/V system also expands with increased m,but it reduces with the decrease of β.In the N/V system,the sliding velocity of the droplet is enhanced with decreased β for m<1.5,whereas for m≥1.5 the trend is reversed owing to the reduced overall driving force caused by the much lower droplet height at smaller β.In the V/N system,the polymer molecules inside the droplet are stretched more significantly near the receding contact lines,which inhibits the droplet's spreading.When m≤1,the wetting area is hardly affected by m or β,but the wetting area increases with increased m or β for m>1.Under the effects of m and β,the variations of the droplet surface area in the V/N system are consistent in trend with those in the N/V system.In both N/V and V/N systems,the droplet slides more slowly at a higher m.Unlik

关 键 词：聚合物驱油 黏弹性流体 液滴 格子玻尔兹曼方法 变形和运移 

分 类 号：TE319[石油与天然气工程—油气田开发工程]