Hi,

I'm currently trying to do some simulations into a conical diffuser (incompressible) and I'd like to try the LES option under FLUENT. But the thing is that I don't know how FLUENT compute in the boundary layer with LES; is it use a wall model (Deardorff, Shuman, ..) (then it's like a wall function approach) or is it solve directly near the boundary (then it's like a 2 layer approach) ? That's quiet important since in consequence I don't know how to mesh in the boundary layer

Thanks in advance,

Andre.

FLUENT will essentially apply linear law (u+ = y+) to your instantaneous velocity if your mesh is fine enough. Otherwise FLUENT applies the log-law. But using fine mesh near the wall will result in high aspect ratio wall cells unless you use really small mesh size in streamwise direction. Near-wall modeling is still a research area and FLUENT adopts a simple practical approach as described above, which works reasonable well when walls play passive roles.