Abstract
The effect of 0-velocity inlet and free-out outlet boundary condition used in the free energy based LBM with large density ratio was investigated in this paper. A static water droplet in the quiescent gas in a gas channel was simulated with both the 0-velocity inlet and free-out outlet boundary condition and the periodic boundary conditions along Z direction of the computational domain. The total mass loss was observed while using the 0-velocity and free-out outlet boundary condition. By comparing with results from the periodic boundary condition, it was proved that both the velocity inlet and the free-out outlet can be the sources of mass un-conservation; the difference of the simulation results between the two types of boundary conditions are small, both boundary conditions can be used in the target simulation.