Hybrid model of lattice Boltzmann and CLSVOF methods for immiscible two-fluid flow

For the development of two-fluid flow simulation with simple and high phase volume conservation, a hybrid model of lattice Boltzmann method (LBM) and coupled level set volume of fluid (CLSVOF) method is proposed. It is confirmed that finite-difference-based CLSVOF is compatible with LBM which shows similar behaviour to those by other simulation methods, and the weakly-compressibility of LBM induces the loss of phase volume. To reduce this volume error, the density distribution correction treatment is implemented in the system. This improved model is validated in cases of immiscible two-fluid flow; an oscillating droplet, a sessile droplet on various wettability surfaces, a droplet flowing through a porous medium, and T-shape channel flow. It is found that incompressible flow fields are well-represented by our improved model. For the case where the compressibility affects largely on the flow, the tendency of the flow is depicted better by unimproved model.