剪切稠化流体内气泡上浮运动特性  

Dynamics of single bubble rising in shear thickening fluid

作　　者：孙涛[1,2] 庞明军[1,2] 陆敏杰 费洋[1,2] 金轩[1,2] SUN Tao;PANG Ming-jun;LU Min-jie;FEI Yang;JIN Xuan(School of Mechanical Engineering;Jiangsu Key Laboratory of Green Process Equipment,Changzhou University,Changzhou 213164,Jiangsu Province,China)

机构地区：[1]常州大学机械工程学院,江苏常州213164 [2]常州大学江苏省绿色过程装备重点实验室,江苏常州213164

出　　处：《化学工程》2019年第11期56-61,共6页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(51376026);江苏省高校“青蓝工程”项目资助;江苏省大学生创新资助项目(20181029032Y)

摘　　要：剪切稠化流体是一种典型的非牛顿流体,研究气泡在其中的运动特性对优化设备结构、提高反应效率具有重要意义。文中采用流体体积(VOF)法,通过改变Gallilei数(Ga)、E tv s数(Eo)与流变指数(n),对牛顿流体(n=1)及剪切稠化流体(n>1)内气泡的形状、尾涡、终端速度和气泡周围液相黏度分布的变化进行了深入的数值研究。结果表明:气泡变形程度和尾涡尺寸随着Ga数或Eo数的增大而增加;剪切稠化效应会阻碍尾涡的形成,减小气泡的尾涡尺寸;气泡周围剪切速率的差异会导致气泡上方及尾部产生高黏度区域,该高黏度区域会随剪切稠化效应的增加而增大;气泡终端速度随Ga数的增大或流变指数n,Eo数的减小而增大。The shear thickening fluid is a typical non-Newtonian fluid.Therefore,it is important to study the dynamics of bubbles in the shear thickening fluid,which can optimize the structure of the chemical reaction devices and improve the reaction efficiency.The volume of fluid(VOF)was implemented to study the bubble shape,wake vortices,terminal velocity and liquid viscosity around bubbles in Newtonian fluid(n=1)and shear thickening fluid(n>1)under different Gallilei number(Ga),E tv s number(Eo)and rheological index(n).The results show that the bubble deformation and the size of wake vortex increase with Ga or Eo increasing;the shear thickening effect hinders the formation of wake vortex and reduces the size of wake vortex;the distribution of shear rate around bubbles leads to a high viscosity region appearing above and behind the bubble,and the area of high viscosity region increases with the shear thickening effect increasing;the bubble terminal velocity increases with Ga increasing or n and Eo decreasing.

关 键 词：剪切稠化流体 气泡运动特性 Eo数 Ga数 流体体积法 

分 类 号：O359.1[理学—流体力学] O373[理学—力学]