Porous wall boundary condition in LES

Henrik

Hello everybody,

I want to perform Large Eddy Simulations of gas flowing in channels with porous walls. Transport of gas between channels (via the porous walls) might be important. Since the walls are not impermeable, the Reynolds stresses at the walls will be different compared to impermeable (normal) walls. Therefore, I am not sure how applicable normal LES wall treatment (i.e. either resolving the flow down to the wall or using wall functions, depending on mesh quality) will be... or whether I could trust the results using any of the porous models in FLUENT (which will essentially just turn off solving the turbulence model's equations in the porous zone and introduce a viscous and/or inertial resistance)...

So, my questions are: 1) How could I (initially) set up wall boundary conditions that more correctly will reflect the fact that the walls are porous and not impermeable? 2) How could I (at a later stage in the process) model the porous walls between the channels, without having to mesh them explicitly?

Does anybody have any experience, information or references on these issues? Any input is highly appreciated!

Thanks in advance, Henrik