Thermocapillary Convection in Low-Prandtl Fluid in an Open Rectangular Cavity Under Microgravity Condition
微重力条件下开口矩形容器的小Pr热毛细对流

The steady thermocapillary convection of gallium melt with a low Prandtl number in an open rectangular cavity under microgravity condition has been investigated by using finite-difference method.The effect of Reynolds number,aspect ratio A of the cavity and the dimensionless height H of the heating side on the isotherms and streamlines of melt has been discussed.Simulation results show that thermocapillary convection has great influence on the temperature distribution of low Prandtl number melt,and affects the process of crystal growth as well.The temperature field varies even if the temperature difference is only 01K.Increasing the temperature difference or Re number,the flow will be increased to make the distribution of the temperature field nonuniformly.As long as there exists the temperature difference on the free surface,thermocapillary convection will be driven no matter how small H is in this way the temperature distribution near the solid-liquid interface is affected.With H and Re increasing,thermocapillary convection develops in the bulk melt.The aspect ratio A has also an important influence on the temperature and flow field.If A is large,the diffusion would play a main role on the front of solid/ liquid interface.