Development of a single-phase free-surface flow model with the improved lattice kinetic scheme.

In this study, we develop a single-phase free-surface flow model with the improved lattice kinetic scheme (LKS) and the volume of fluid (VOF) method. We implement the piecewise linear interface calculation (PLIC) algorithm to reconstruct the interface. The gas phase velocity is extrapolated from the liquid phase velocity using a velocity extension method and the signed distance function (SDF) to advect the VOF function. We calculate the SDF with the level-set reinitialisation method, and the VOF function is used as the initial profile. We discuss the advantages of the improved LKS in terms of the free-surface boundary condition by means of distribution functions, which conflict in interface cells in conventional streaming and collision processes in the lattice Boltzmann method (LBM). The proposed free-surface model is verified with well-known advection benchmark problems. We also simulate a static water problem and dam break flow. The proposed model accurately calculates the dam break surge front. Although the surge front position depends on the spatial resolution in the conventional LBM free-surface model, the improved LKS results are approximately the same regardless of the resolution. This is a critical difference between the proposed and conventional LBM models and represents a unique feature of the improved LKS. • A single-phase free-surface flow model by the improved LKS is developed. • Conflicts of the distribution function do not arise because the boundary conditions are given as the macroscopic variables. • The velocity field is extended by the SDF and the advection of the VOF function is calculated by the PLIC approach. • The proposed model is stable without the turbulence model and agrees well with the experimental results. [ABSTRACT FROM AUTHOR]