[keitaro7_14]

Hello everyone,

I'm trying to simulate a wind velocity field in a scenario where there is a porous wall. However, I'm not totally convince, since I think that the results are not realistic.

If I simulate the velocity field in a scenario with a wall (no porous), using simpleFoam (steady-state turbulent k-epsilon simulation), the behaviour seems reallistic.




The initial U profile is recovered near the right boundary (Yes, I know that I should enlarge the domain to achieve a quasi totally recovered profile).




The nut field is also coherent. The turbulence increases near the wall due to the vortex formation, and it begins to disappear near the right boundary (again, I should enlarge the domain)

However, If I use Porousbafflepressure BC to add the porous wall, or if I use porousSimpleFoam to add the porous wall implicitly (I have checked that the results are identical), the result is strange for me. With a moderate pressure drop (Dcoef = 10^5), this is the result:



The U profile is recovered (a little bit) near the right boundary. But it is needed 1km practically. Well, probably it is true, I don't know.



However, the corresponding nut field is very strange. Why is the vortex created so far of the wall? Is it normal? How can it be formed at 800m from the source of discontinuity? I'm freaking out!

The boundary conditions are very simple. No slip in the atmosphere, a uniform profile in the inlet, a zero gradient in the outlet. I think it is not the problem.

Can someone with more experience than me enlighten me? I only want to know if it seems realistic. My main doubt is related to the nu field in the last picture. Can the nu field be formed so far from the wall?

Thank you so much!!