Lattice Boltzmann Model Using Two Relaxation Times for Shallow-Water Equations
Lattice Boltzmann Model Using Two Relaxation Times for Shallow-Water Equations
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DOI：
10.1061/(asce)hy.1943-7900.0001065
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发表时间：
2016-02
影响因子：
2.4
通讯作者：
Y. Peng;JianMing Zhang;J. Zhou
中科院分区：
文献类型：
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作者：
Y. Peng;JianMing Zhang;J. Zhou
提出了求解无湍流浅水方程的双松弛时间抽象格子Boltzmann方法(LABSWETRT)。通过对三种典型的层流流动情况的模拟，验证了所描述的模型的有效性：一维定常绕流、二维非定常溃坝流动和圆柱绕流。预测结果与解析解或实验解吻合较好。此外，还详细比较了LABSWETRT和格子Boltzmann方法(LABSWE)在求解浅水方程时的性能。研究表明，对于2D情况，前者比后者更稳定。文中还对两种松弛时间的不同组合进行了研究，为获得较好的数值稳定性，推荐了最优的松弛时间。这项研究表明，LABSWETRT中的额外松弛时间可以提高层流浅流数值模拟的稳定性，所用的步骤几乎与LABSWE中的一样简单。
AbstractA lattice Boltzmann method with two relaxation times for shallow-water equations (LABSWETRT) without turbulence is proposed. The described model is validated through simulations of three typical cases with laminar flows: 1D steady flow over a bump, 2D unsteady dam-break flow, and flow around circular cylinder. Good agreement between prediction and analytical or experimental solutions are obtained. In addition, the performance of the LABSWETRT and the lattice Boltzmann method for shallow-water equations using a single relaxation time (LABSWE) is compared in detail. Studies have shown that the former is more stable than the latter for 2D cases. Different combinations of the two relaxation times are also studied and the optimized one is recommended for good numerical stability. This study demonstrates that the additional relaxation time in the LABSWETRT can improve the stability of simulations for laminar shallow flows using a procedure almost as simple as that in the LABSWE.