低充水液舱晃荡气垫效应的数值分析

为了研究空气可压缩性对液仓晃荡和流体动力载荷的影响,建立了基于NS方程和VOF方法的自由表面流动数学模型,其中气相可作为可压缩介质。通过单涡演化、溃坝和受迫晃荡三个典型算例的计算,验证了数值方法的有效性。与现有的实验结果对比发现,考虑气相可压缩的两相流模型能合理地反映液仓侧壁的压力振荡过程,而基于气相不可压缩假定的数值模型则无法给出合理的结果。采用空气可压缩的两相流模型,给出了不同背景压强作用下液舱晃荡形态及液体对壁面的拍击力。通过比较壁面监测点的压力时间过程线的计算结果和现有的实验数据,表明考虑空气可压缩性的两相流模型可以很好地预报最大压力峰值,并较合理地给出压力振荡过程,因此有必要在液仓晃荡与流动动力预报中考虑空气的气垫效应。

Numerical investigation of air cushion effects on low filling sloshing impacts

To investigate the effects of air compressibility on the two phase low filling sloshing,a two dimensional numerical model was developed based on the NS equations and VOF method,in which the air phase could be treated as a compressible fluid.Comparing with experimental results,the air-entrapment and its effects on hydrodynamic loads could not be well predicted with the incompressible air assumption.The existence of compressible air cushion will result in the pressure oscillation on the sidewalls during slosh...