环形池内具有自由表面的双层流体热毛细对流  

Thermocapillary convection in annular two-layer system with upper free surface

作　　者：唐经文[1] 周永利[1] 张文杰[1] 李友荣[1] 

机构地区：[1]重庆大学动力工程学院低品位能源利用技术及系统教育部重点实验室,重庆400044

出　　处：《热科学与技术》2012年第1期20-26,共7页Journal of Thermal Science and Technology

基　　金：国家自然科学基金资助项目(50776102);重庆大学211工程"三期建设"资助项目(S-09101)

摘　　要：采用数值模拟方法研究微重力条件下环形双层液体内存在水平温度梯度时的热毛细对流及其稳定性。流体为5cSt硅油/HT-70,外壁被加热、内壁被冷却,下固壁和上自由表面均绝热。结果表明:当Ma较小时,流动为稳定的轴对称流动;随着Ma和深宽比的增大,流动加强,等温线发生强烈的非线性变形;当Ma超过临界值后,流动转化为非稳定的多胞流动;随着Ma和深宽比的增大,速度振荡增大并向热壁方向运动,多胞流动结构占据区域拓展;流动转变的临界Ma随着深宽比的增大而减小。The thermocapillary convection and stability under microgravity conditions in the annular two horizontal liquid layers with upper free surface subjected to a radial temperature gradient was investigated numerically.The fluids are 5cSt silicone oil and HT-70,and the pool was heated from the outer cylindrical walls and cooled at the inner cylinder surface.Both bottom rigid wall and top free surface are adiabatic.The results show that the flow is stable axisymmetrical flow at a small Marangoni number.With the increase of the Marangoni number and the aspect ratio,the flow is significantly enhanced and a strong nonlinear deformation of the isotherms happened.When the Marangoni number exceeds a critical value,the flow transits to the unstable multi-cellular flow,the velocity oscillation amplitude increases and the oscillation wave propagates to the hot wall.The critical Marangoni number decreases with the increase of the aspect ratio.

关 键 词：数值模拟 热毛细对流 双层流体 自由表面 

分 类 号：TK124[动力工程及工程热物理—工程热物理]