中文摘要：

为了了解开口圆形浅池内低Rr流体的热毛细对流基本规律，利用有限差分法进行了三维直接数值模拟。结果表明，当侧壁温度不均匀性较小时，流动为稳定的三维流动。当温度不均匀性超过某一临界值后，流动将转化为振荡的三维流动，为此，确定了流动转化的临界条件，分析了三维振荡热毛细对流的基本特性。发现在自由表面Marangoni效应作用下，冷壁附近温度和速度波动的滞后是引起三维振荡流动的主要原因。

英文摘要：

In order to understand the characteristics of thermocapillary convection, a series of unsteady three-dimensional numerical simulations of thermocapillary convection of low Prandtl number fluid in a shallow cylindrical pool, with an azimuthal temperature non-uniform, an adiabatic solid bottom and free surface, were conducted. The simulation results indicate that thermocapillary convection is steady three-dimensional flow at the small temperature non-uniform. When temperature non-uniform number exceeds some critical value, the flow will undergo a transition to three-dimensional oscillatory flow. The critical conditions for the flow transition were determined. Details of the flow and temperature fields were discussed, and oscillation frequencies were also exhibited.