Three-Dimensional Numerical Method for Simulating Large-Scale Free Water Surface by Massive Parallel Computing on a GPU

Abstract

Water wave dynamics and its engineering application have always been a key issue in the field of hydraulics, and effective and efficient numerical methods need to be proposed to perform three-dimensional (3-D) simulation of large-scale water fluctuation in engineering practice. A single-phase free-surface lattice Boltzmann method (SPFS-LB method) is coupled with a large-eddy simulation approach for simulating large-scale free water surface flows, and the simulation is accelerated on a GPU (graphic processing unit). The coupling model is used to simulate the evolution process of dam-break wave after complete and partial dam-break. The formation mechanism of horizontal and vertical vortices in water after partial dam-break and the advance and evolution process of dam-break flow on non-contour riverbed are analyzed. The method has been verified to be reasonable and can obtain a more accurate time curve of water level fluctuation. Applying this method to practical arch dams, discharge coefficients consistent with empirical formulas can be obtained by comparison and analysis, and the surface flow phenomena (such as tongue diffusion, surface fragmentation, and surface fusion) can be well simulated by this method. In addition, based on the key technology of parallel computing on a GPU, the implementation of the SPFS-LB model on a GPU unit achieves tens of millions of lattice updates per second, which is over fifty times higher than that on a single CPU chip. It is proved that the proposed method for large-scale water fluctuations can be used to study practical engineering problems. The mathematical model method realizes the efficient and accurate simulation of practical physical problems.

Experimental and Numerical Analysis of a Dam-Break Flow through Different Contraction Geometries of the Channel

“…Fine meshes can be necessary in numerical simulations to represent irregular topographies and to obtain more accurate results. On the other hand, more computational efforts and times are required for 3-D solutions of large-scale real-case dam-break problems in the presence of artificial and natural obstacles such as bridges, buildings, dikes, and trees [39,51,52]. In order to model flow around 3D structures such as bridges using fine mesh to capture localized flow details, the hybrid models combining RANS-based 3D flow and shallow water models in one simulation can also be used to reduce the computation time [44].…”

A 1D–2D Coupled Lattice Boltzmann Model for Shallow Water Flows in Large Scale River-Lake Systems

“…where the weight factor w α = {4/9, 1/9, 1/9, 1/9, 1/9, 1/36, 1/36, 1/36, 1/36}. Water depth and velocity of the fluid are given by Equation (5). The multi-relaxation time (MRT) collision operator has been adopted [33].…”