Validation of the MRT-LBM for three-dimensional free-surface flows: an investigation of the weak compressibility in dam-break benchmarks
Validation of the MRT-LBM for three-dimensional free-surface flows: an investigation of the weak compressibility in dam-break benchmarks
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DOI：
10.1080/21664250.2019.1672124
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发表时间：
2020-01
影响因子：
2.4
通讯作者：
Kenta Sato;S. Koshimura
中科院分区：
文献类型：
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作者：
Kenta Sato;S. Koshimura
摘要自由表面流问题出现在许多灾害模拟中，如海啸在城市地区的内陆渗透。由于这些问题的强非线性和高阶物理现象，模拟模型必须是非静力学的、三维的和高分辨率的。然而，由于不可压Navier-Stokes流体模型中的压力泊松方程，使得基于传统计算流体力学（CFD）求解Navier-Stokes方程的三维大规模海啸模拟具有挑战性。格子玻尔兹曼方法（LBM）是一种替代的模拟工具，作为一种完全显式和有效的方法而备受关注。LBM不必迭代求解压力泊松方程，因此被认为在执行高性能三维海啸模拟时比其他方法具有优势。在目前的研究中，我们开发了一个完全显式的自由表面模型，使用LBM，其中使用更先进的多松弛时间（MRT）碰撞模型，沿着与分段线性界面计算（PLIC）的方法。通过经典的溃坝问题，我们验证了适当的参数设置，包括弱压缩性，海啸模拟。基准试验表明，该模型能准确地模拟三维溃坝流动，并将压缩性降控制在二阶马赫数范围内。
ABSTRACT Free-surface flow problems occur in numerous disaster simulations, such as tsunami inland penetration in urban areas. Simulation models for these problems must be non-hydrostatic, three-dimensional and highly resolved because of the strong non-linearity and higher-order physical phenomena. However, three-dimensional large-scale tsunami simulations based on conventional computational fluid dynamics (CFD) solving the Navier-Stokes equations are challenging due to the pressure Poisson equation in incompressible Navier-Stokes fluid modeling. The lattice Boltzmann method (LBM) is an alternative simulation tool that is attracting attention as a fully explicit and efficient approach. The LBM does not have to iteratively solve the pressure Poisson equation and is therefore considered to have an advantage over other methods when executing high-performance three-dimensional tsunami simulations. In the current study, we developed a fully explicit free-surface model using the LBM in which the more advanced multiple-relaxation-time (MRT) collision model is used, along with the piecewise linear interface calculation (PLIC) approach. Through classic dam-break problems, we validated the appropriate parameter settings, including the weak compressibility, for tsunami simulations. The benchmark tests showed that our model accurately simulates the three-dimensional dam-break flows and controls the compressibility drop in the second-order value of the Mach number.