Numerical simulation of two-layered liquid sloshing in tanks under horizontal excitations
Numerical simulation of two-layered liquid sloshing in tanks under horizontal excitations
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DOI：
10.1016/j.oceaneng.2021.108768
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发表时间：
2021-03
影响因子：
5
通讯作者：
Dongming Liu;P. Lin;Mi-An Xue;Lin Cheng;J. Lian
中科院分区：
文献类型：
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作者：
Dongming Liu;P. Lin;Mi-An Xue;Lin Cheng;J. Lian
建立了一个研究水平外激励下两层液体晃动的数值模型NEWTANK。该模型在非惯性坐标系下求解外部激励下的空间平均nse。数值求解采用两步投影法，压力场泊松方程采用Bi-CGSTAB技术求解。提出了一种多层流体体积法，可同时跟踪层状液体之间的自由表面和界面。为了验证模型的准确性，将仿真结果与线性解析解和实验数据进行了比较。当响应幅值在线性范围内时，得到了较好的一致性。然而，当非线性变强时，由于能量从初级模态向高级模态的非线性传递，与解析解的偏差会很大。进一步研究发现，对于两层液体晃动，存在两个固有频率，较小的频率与下层液体的响应有关，较大的频率与上层液体的响应有关。因此，不同的外部激励频率可能会引起上层共振、下层共振或两层共振，每种共振都表现出非常不同的模式和层之间的能量输运模式。最后，对具有破碎自由表面和界面的剧烈三维晃动进行了模拟和讨论。
A numerical model NEWTANK has been developed to study two-layered liquid sloshing under horizontal external excitations. The model solves spatially averaged NSEs on a non-inertial coordinate for external excitations. The two-step projection method is employed in numerical solutions, and the Poisson equation for pressure field is solved by Bi-CGSTAB technique. A multi-layered volume-of-fluid method is proposed to track both free surface and interface between layered liquids simultaneously. In order to validate the accuracy of the model, the simulated results of sloshing responses are compared with linear analytical solutions and experimental data. Good agreements are obtained when response amplitude is within linear regime. However, when nonlinearity becomes strong, deviation from analytical solution will be large due to nonlinear energy transfer from the primary mode to higher modes. Further investigation reveals that for two-layered liquid sloshing, there exist two natural frequencies with the smaller one related to response of lower layer liquid and the larger one upper layer. Therefore, different external excitation frequencies may induce upper-layer resonance, lower-layer resonance or resonances of both layers, each of which exhibits very different patterns of energy transport between modes and layers. Finally, a violent 3-D sloshing with broken free surface and interface is simulated and discussed.