Validation of the MRT-LBM for three-dimensional free-surface flows: an investigation of the weak compressibility in dam-break benchmarks

Kenta Sato, Shunichi Koshimura

Research output: Contribution to journalArticle

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.

Original languageEnglish
Pages (from-to)53-68
Number of pages16
JournalCoastal Engineering Journal
Volume62
Issue number1
DOIs
Publication statusPublished - 2020 Jan 2

Keywords

  • Lattice Boltzmann method
  • computational fluid dynamics
  • dam-break flows
  • free-surface flows
  • multiple-relaxation-time
  • tsunami

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Modelling and Simulation
  • Ocean Engineering

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