I am just wondering how the open boundary is usually treated in SC multi-component model for applications such as moving droplet or multiphase flow.
It occurs to me that when pressure boundary is applied (rho=1 for initially occupying fluid and rho=0 for the other), the droplet/invading fluid cannot exit the simulation domain through the boundary. Therefore, the zero-gradient Neumann boundary is probably more suitable in this case. However, I am not able to find relevant literature on this topic, except a short thread here (https://www.researchgate.net/post/How_can_I_deal_with_multicomponent_open_boundaries_in_LBM).
Can someone suggest some literature or their opinion on implementing open boundaries for SC multi-component model please?