用MPS方法数值模拟低充水液舱的晃荡

Numerical simulation of liquid sloshing in low-filling tank by MPS

液体晃荡是一种非线性的自由面流动现象。在低充水率下,由于液体具有很大的运动空间,晃荡现象具有强烈的非线性特征,自由面的变形较大,剧烈时甚至会翻卷和破碎,这给数值模拟带来很大挑战。本文基于移动粒子半隐式法(Moving Particle Semi-Implicit,MPS)对低充水率的液舱晃荡问题进行了数值模拟。结果表明:当激励频率等于共振频率时,液体撞击到了液舱的顶板,并出现了飞溅现象,此时液体对侧舱壁产生了较大的抨击压力;在低于共振频率时,自由面出现了破碎波及波前的翻卷和融合等现象,抨击压力相对较小。计算结果表明,MPS方法能够很好地预测晃荡引起的拍击现象,数值计算得到的压力能够与实验结果很好地吻合。在自由面的追踪上,MPS方法具有很大的灵活性,能够很好地处理自由面的破碎、融合及液体的飞溅等流动现象。

Liquid sloshing is a kind of nonlinear free-surface flows.In low-filling tank,sloshing shows strong nonlinearity due to the large space for liquid motion.The free surface will happen to be deformed greatly,merged and broken.Simulation of such complicated flows is a challenging task.In this paper,the liquid sloshing in low-filling tank is simulated based on Moving Particle Semi-Implicit（MPS） method.Results show that the liquid impacts the ceiling of the tank,and splashes,when the oscillation frequency is equal to the natural frequency.A large impact pressure on the side wall is observed.At a lower oscillation frequency,the wave in the tank is broken,and turns over.A lower impact pressure on the side wall is measured.Numerical results illustrate that the MPS method can predict the impact behavior induced by liquid sloshing.The calculated pressure is in good agreement with experimental data.The presented MPS method is proved to have good flexibility in dealing with the complex free surface flows with broken and merged waves.