Numerical simulation of the liquid column collapse in the reservoirs of different shapes

The numerical simulation of three different cases of liquid column collapse is carried out. These are the collapses of hexahedral liquid column in a cubic reservoir, cylindrical liquid column, and ringshaped liquid column in a cylindrical reservoir. Mathematical modeling is based on the volume of fluid method. The obtained results show that the lower the liquid column, the longer the liquid front reaches the opposite wall of the reservoir. The velocity maximum is observed at the flow front. The velocity of the front depends on the shape of liquid column in the initial stage. The dimensionless time of passing dimensionless distance of 3.0 in a cylindrical reservoir is equal to 2.58 and 1.76 for diverging and converging waves, respectively, while in a cubic reservoir, the time is equal to 2.09. The time dependences for position of the liquid front, liquid level, pressure value at the control point on the reservoir wall in the process of liquid column collapse are obtained. It is shown that the liquid level drop occurs faster in the case of cylindrical column collapse, and the flow flowing onto the wall is less deep and less speedy.