Application of the lattice Boltzmann method for large-scale hydraulic problems

Purpose - The purpose of this paper is to prove the validity of the front-tracking variant of the lattice Boltzmann method (LBM) to simulate free surface hydraulic flows (i.e. dam break flows). Design/methodology/approach - In this paper, an algorithm for free surface simulations with the LBM method is presented. The method is chosen for its computational efficiency and ability to deal with complex geometries. The LBM is combined to a surface-tracking technique applied to a fixed Eulerian mesh in order to simulate free surface flows. Findings - The numerical method is then validated against two typical cases of environmental-hydraulic interest (i.e. dam break) by comparing LBM results with experimental data available in literature. The results show that the model is able to reproduce the observed water levels and the wave fronts with reasonable accuracy in the whole period of the transient simulations, thus highlighting that the present method may be a promising tool for practical dam break analyses. Originality/value - Even if the main philosophy of the proposed method is equal to the volume of fluid technique usually coupled to Navier-Stokes models, no additional differential equation is needed to determine the relative volume fraction of the two phases, or phase fraction, in each computational cell, as the free-surface tracking is automatically performed. This results in a method very simple to be coded with high computational efficiency. The results presented in this paper are the first, to the best of the authors' knowledge, in the field of hydraulic engineering.