重力水平对热毛细-浮力对流耗散结构的影响

Effect of Gravity Level on Flow Pattern of Thermocapillary-Buoyant Convection

为了了解重力水平对环形液池内热毛细-浮力对流耗散结构的影响,利用有限容积法进行了非稳态三维数值模拟,环形液池外壁被加热,内壁被冷却,流体为0.65cSt硅油,其Pr数为6.7。结果表明,在微重力条件下,流动为三维振荡流动;当重力水平增加到0.1go时,流动结构转化为沿周向运动的一组滚胞,其轴线与温度梯度方向一致;当重力水平增加到0.5go时,流型则为一组静止的滚胞;当重力水平继续增加到3go时,流动转变为稳定流动。

In order to understand the effect of gravity level on the flow pattern of thermocapillary- buoyant convection in an annular pool, a series of unsteady three-dimensional numerical simulations were carried out with finite-volume method. The pool was filled with the 0.65cSt silicone oil （Prandtl number Pr----6.7）, and heated from the outer cylindrical wall and cooled at the inner wall. The simulation results show that the three-dimensional oscillatory flow appeared at micro-gravity. When g=O.lgo, the flow pattern transits extended roll cells travelling in the azimuthal direction. If the gravity level increases to 0.Sgo, the stable three-dimensional flow happened. Further, at g=3.0go, the thermocapillary-buoyant convection transits the steady axially symmetric flow.