基于计算流体动力学(CFD)方法,利用体积流(VOF)模型对矩形流道内单气泡及双气泡运动进行了数值模拟,并分析了其运动规律。模拟结果与前人实验观测结果相符。单气泡上升过程中经历加速上升和摆动上升两个阶段,其稳定速度与Eo数相关,摇摆阶段的气泡轨迹类似于周期性的正弦曲线。上下分布的气泡会发生聚并现象,水平对称分布的气泡上升过程中会出现规律的分离、靠近现象。研究表明:该方法能够准确地模拟气泡的运动,获得气泡运动的机理,可以作为进一步研究自然循环中不同浮升力下气泡分布机理研究的基础。 Based on computational fluid dynamics (CFD) method, a single bubble and a double bubble in a rectangular flow channel are numerically simulated by using the volume flow (VOF) model and their movement rules are analyzed. The simulation results are consistent with the previous experimental observations. The single bubbles rise exponentially with increasing Eo, and the bubble trajectory is similar to the periodic sinusoidal in the swing phase. The bubbles that are distributed up and down will converge and the bubbles will rise horizontally and symmetrically. As a result, there will be regular separation and close phenomenon. The results show that this method can accurately simulate the movement of bubbles and obtain the mechanism of bubble movement, which can be used as the basis for further study of bubble distribution mechanism under different buoyancy forces in natural circulation.