constant gradient rate bounday
 

Hi. I am new to cfx and I am trying to apply a constant gradient rate boundary in an inlet, but i can't find a B.C. like this. Is there any way to apply such a B.C. in cfx?

thank you

Re: constant gradient rate bounday
 

Dear Kostas,

I imagine you mean a constant flux, that is grad(phi).normal vector . Then, you can use the Flux in condition, and divide by the "diffusion coefficient" of that equation.

Would you mind explaining what guarantees a gradient at an inlet boundary? Is it for an additional variable with no advection?

Good luck,

Opaque

Re: constant gradient rate bounday
 

For which equation?

Re: constant gradient rate bounday
 

thnks for the reply

My problem is o buoaunt flow between vertical parallel plates with openings on the top (outlet) and the botton (inlet).

I want to apply a classic Neumann outlet b.c. for the velocity and pressure (without prescribing values for velocity or pressure).

Thank you