Abstract This paper investigates large amplitude sloshing in a prismatic tank with or without a baffle by a Cartesian grid based three-dimensional (3D) multiphase flow model. In this model, an improved ghost cell method with a unified reconstruction scheme is developed to enforce boundary conditions on the slope walls of the tank. Arbitrary shape tanks and internal structures can be treated on the Cartesian grid, instead of the body-fitted grid. A 3D gradient-augmented level set (GALS) method is presented to capture highly nonlinear free surfaces. To validate the accuracy of the present ghost cell method, uniform flows around a sphere are simulated. An approximate second-order accuracy in space is achieved. Then, nonlinear sloshing induced by rolling excitations in the 3D prismatic tank is simulated. Satisfactory convergences of grid sizes and time steps are obtained. Also, good agreements are achieved between the present results and the experimental data for five filling water depths. In addition, highly nonlinear sloshing phenomena are captured such as plunging waves and wave beating. Furthermore, the variation of the excitation frequency with the pressure amplitude, and the effects of the baffle height on the impulsive pressure and the wave elevation are studied.

中文翻译：

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基于笛卡尔网格的三维多相流模型对棱柱罐非线性晃荡的数值模拟

摘要 本文通过基于笛卡尔网格的三维 (3D) 多相流模型研究了带或不带挡板的棱柱罐中的大振幅晃荡。在该模型中，开发了一种具有统一重建方案的改进鬼单元法，以在储罐的斜坡壁上强制​​执行边界条件。任意形状的坦克和内部结构可以在笛卡尔网格上处理，而不是贴身网格。提出了一种 3D 梯度增强水平集 (GALS) 方法来捕获高度非线性的自由表面。为了验证本鬼细胞方法的准确性，模拟了球体周围的均匀流动。实现了近似的空间二阶精度。然后，模拟了由 3D 棱柱罐中的滚动激励引起的非线性晃荡。获得了令人满意的网格大小和时间步长收敛。此外，目前的结果与五个充水深度的实验数据之间取得了良好的一致性。此外，还捕获了高度非线性的晃荡现象，例如突降波和跳动。此外，还研究了激励频率随压力幅值的变化，以及挡板高度对冲击压力和波高的影响。