Lattice Boltzmann simulation of free surface flow impact on a structure.

Abstract

Liquid impact on a rigid wall is a common feature in the context of marine structures, as most of them are exposed continuously to breaking waves. In the present paper, a comparison and analysis of the impact load estimates obtained from free surface lattice Boltzmann (LB) simulation with the experimental measurements from available literature have been reported. Initially, two-dimensional simulation of the dam break impact on the wall is performed with two different LB models: BGK-F1: a Bhatnagar-Gross-Krook (BGK) collision operator with the force scheme of Buick and Greated [Phys. Rev. E 61, 5307 (2000)1063-651X10.1103/PhysRevE.61.5307], and MRT-F2: a multiple relaxation time (MRT) operator with the force scheme of Guo etal. [Phys. Rev. E 65, 046308 (2002)1063-651X10.1103/PhysRevE.65.046308]. The pressure estimates obtained from BGK-F1 over MRT-F2 are closer to the measurements, though the other key parameters, such as the waterfront evolution and the free surface profile, have not shown significant variations. Furthermore, the three-dimensional dam break simulation has been performed using BGK-F1 for three test cases: (i) impact on a wall, (ii) impact on a rectangular obstacle, and (iii) impact on a tall tower. In all the test cases, the load estimates are in agreement with the experimental measurements.