The oscillation of liquid/gas free surface in a partially filled storage tank caused by an abrupt drop of gravity level is of critical importance for the fluid management in space. In the present study, the dynamic behavior of free surfaces in a model tank (tube) is numerically investigated using volume of fluid (VOF) method in the context of dynamic contact angle (DCA) model. It is concluded that the dynamic behavior of free surface could be captured pretty well using the selected DCA model, as shown by comparison with the results of Drop Tower Beijing experiment. The temporal evolution of free surface reproduces exactly the characteristics of damping oscillations. The detailed dynamic deflections of meniscus reveal crucial dependency between the oscillation frequency of free surface and the boundary condition in the contact line. The oscillation frequency increases when the range of the moving contact line transfers from the spherical-shaped part to the cylindrical part of the tank and maintains constant when the moving contact line remains always at the cylindrical part of the tank. Meanwhile, the oscillation amplitude decreases in line with the increase of oscillation frequency.

由重力水平的突然下降引起的部分填充的储罐中的无液/气表面的振动对于空间中的流体管理至关重要。在本研究中，在动态接触角（DCA）模型的背景下，使用流体体积（VOF）方法对模型罐（管）中自由表面的动力学行为进行了数值研究。结论表明，与Drop Tower Beijing实验的结果相比，使用所选的DCA模型可以很好地捕获自由表面的动态行为。自由表面的时间演变精确地再现了阻尼振荡的特征。弯月面的详细动态变形揭示了自由表面的振动频率与接触线中的边界条件之间的关键依赖性。当移动接触线的范围从罐的球形部分转移到罐的圆柱形部分时，振荡频率增加，并且当移动接触线始终保持在罐的圆柱形部分时，振荡频率保持恒定。同时，振荡幅度随着振荡频率的增加而减小。