Learning Forum

[yz12b]

I have searched online but found few solutions. We know the v-profile at the BC, in order to implement zero-vorticity, we'd like to add du/dy to the BC based on the v-profile. It seems the only way to do it is to use the UDF. But the UDF manual is very hard to follow.

I think it is something like DEFINE_UDS_FLUX, and C_U_G(c,t)[1] is for du/dy. But I have no clues to complete the UDF. Hope someone can help. Thanks in advance.

[Rob]

Have a look at the DEFINE_PROFILE example, and also have a look at Expressions in the recent releases.

[yz12b]

HI Bob, I checked but couldn't find an example for this. I also check the UDF for shear stress, which is similar, but no clues yet. What do you mean by 'Expressions'? Thanks.

[Rob]

If you just want to vary velocity with position then there is an example in the manual: it's THE example for the macro I suggested.