[sjlouie91]

Dear Foamers,


I am now trying to use outletStabilised scheme in my LES case. However, when I set the scheme as
div(phi, U) Gauss outletStabilised
it shows that discretisation scheme not specified. But this scheme is among the valid schemes.


So I don't know how I can deal with this problem. Has anyone used this scheme before?

[clapointe]

If I remember correctly, it "modifies" a scheme -- so you would need to specify, for example, Gauss outletStabilised linear. However, if stabilization is required at the outlet it might be worth double checking the bc's before relying on the outletStabilised to (hopefully) do it for you.

Caelan

[sjlouie91]

Originally Posted by clapointe

If I remember correctly, it "modifies" a scheme -- so you would need to specify, for example, Gauss outletStabilised linear. However, if stabilization is required at the outlet it might be worth double checking the bc's before relying on the outletStabilised to (hopefully) do it for you.

Caelan

Thank you so much.


Actually before I am trying to use outletStabilised scheme, I used linear scheme. As my case is running in a truncated domain, the outlet is 2 chord length away from the airfoil. So I used advective boundary condition for velocity and pressure, and ZG for nut. However, it went well for about 8-9 flow-through time, and after that nut begins to oscillate from the wake and finally affected the pressure side of the airfoil. But there is no reflection flow as I set advective BC for velocity.



Do you have any idea about how to solve this problem?

[clapointe]

Short of extending the domain to make the outlet further from the airfoil, retaining stability will likely be tricky. There are a number of numerical games you could start playing, but whether those are warranted (over changing the mesh) is another matter...

Caelan