本文通过数值模拟的方法，研究了零重力条件下半浮区液桥内熔体热毛细对流的演化规律。在液桥的高度L和温差ΔT保持不变的情况下，通过改变液桥的半径R来改变液桥的高径比（Ar=L/R）。随着高径比Ar的变化，液桥内的对流表现出不同的流动特征。在Ar=0.5时，热毛细对流处于三维稳态；在Ar=1时，流场和温度场从稳态模式向非稳态周期多频振荡模式转变，它们之间的频率关系满足倍频关系（fn=nf1）；在Ar=1.25时，监测点的速度振荡频率增大，表现为较小幅度的振荡模式，且温度振荡消失。

In this paper, the evolution of thermocapillary convection in melt of half-floating zone liquid bridge under the condition of zero gravity was studied by means of numerical simulation. Under the condition that the height L of the liquid bridge and the temperature difference ΔT remain unchanged, the aspect ratio (Ar=L/R) of the liquid bridge can be changed by changing the radius R of the liquid bridge. The convection in the liquid bridge exhibits various flow characteristics with the change of the aspect ratio Ar. Thermocapillary convection is in a three-dimensional steady state when Ar=0.5. The flow field and temperature field change from the steady state mode to the unsteady periodic multi-frequency oscillation mode satisfying the frequency doubling relationship (fn=nf1) when Ar=1. When Ar=1.25, the velocity oscillation frequency of the monitoring point increases, showing a smaller amplitude oscillation mode, and the temperature oscillation disappears.