Hello friends
Does anyone know Multi-reflection boundary and the benefit it has over Standard Bounce Back? I am modeling flow through porous media Does this method have any benefit for me?
Thanks a lot in advanced
Amir
I don’t know much about multi-reflection boundaries at the moment but I think it is important to be aware that there are a number of problems when using standard bounce-back (and probably multi-refection boundaries too because it’s probably a form of bounce-back) with the BGK collision operator. In particular, it gives you a non-zero velocity at the wall. This is NOT Navier slip, or indeed any other form of slip - it is simply a numerical error due to the inadequacies of the single relaxation time approach. If I remember correctly, multi-reflection boundaries allow for better resolved solutions on coarser grids, and if this is correct then it is likely to be useful for pore-scale flows. Either way, you need to remember that you generally need more than one relaxation time to obtain accurate results,