Numerical investigation of a combined lattice Boltzmann-level set method for three-dimensional multiphase flow

We simulate rising bubbles using a hybrid lattice Boltzmann scheme based on the lattice BGK model coupled with the level set method (Thommes et al., 2009. A lattice Boltzmann method for immiscible multiphase flow simulations using the level set method. Journal of Computational Physics). This method uses special boundary conditions at the interface between the two phases which realise the macroscopic jump conditions on the kinetic level and incorporate surface tension into the model. Previous experience with the approach has already demonstrated that it is feasible over a wide range of density and viscosity differences. We utilise this method to simulate the classical immiscible multiphase problem of rising bubbles driven by buoyancy forces. In particular, simulations with large density ratios are performed. The numerical results are compared with available reference solutions.