Modified ghost fluid method on LBM with reduced spurious pressure oscillations for moving boundaries

Abstract

A modified ghost fluid (MGF) method for reducing the spurious pressure oscillations in moving boundaries is proposed on the lattice Boltzmann method (LBM). The primary cause of these oscillations is the violation of the boundary geometric conservation law for sharp-interface immersed boundary. We introduce a simple weight strategy into GF method to strictly enforce geometric conservation. The weight strategy reduces the abrupt change of the distribution function on the boundary node when passing through the moving boundary. Some simulations are shown to test the validity of the method. The results illustrate that the modified method maintains the same validity as the GF and reduces the spurious pressure oscillations near the boundaries.