Set the inflow condition from the outflow
 

Hi, I want to get the outflow velocity value and set them as the inlet velocity. For example, the distance between the inlet and outlet is 10 meters. I will set U_inlet(x,y,z,t) = U_outlet(x+10,y,z,t). How to make it? I have read the User Fortran. But I do not know how to get a obtain a velocity from point(x,y,z). Can you help me? Thank you!

No, this is not the way to do it. You will need to use a periodic boundary condition. V12 has a lot of extra features for this type of boundary to do exactly what you are trying to do.

Hi ghorrocks, thank you. I find that in V12 they are rotational periodic condition such as turbo. But actually I want to rescale the outflow velocity and reintroduce it to the inlet. I am afraid that 's not regular periodic interface operation. So is there any way to realize it?

Can you explain what you are trying to do? What you are describing does not sounds physically possible as it does not conserve mass.

I want to do a transient simulation. The inflow velocity at the inlet is computed from the outflow velocity at the outlet on every time step. For example, U_inlet(x,y,z,t)=2*U_outlet(x,y,z,t). This is just an example. Actually the transformation is a little complex and not just multiply 2. Is this clear?