Hi,

I'm having a problem, which probably has a simple solution. I'm modeling a vertical flow profile in a river, which has a velocity inlet, outlet, bottom wall, and atmospheric pressure on the top. Initially, I set the top as a wall, but that gives an incorrect profile of what's actually happening. How can I set an atmospheric pressure boundary condition for the top? I've tried to label it as a pressure inlet and set it to atmospheric pressure, but I receive a warning of having a pressure inlet along with a general outlet. And the solver won't initialize. Is there a better way of defining these boundary conditions?

Thanks, veronica

Hi Veronica,

your case is similar to the open channel flows..! In such cases...you can choose the operating pressure to be atmospheric...and for top boundry..i.e. for water surface...set symmetry boundry condition...!It works...! else you can go for wall BC...but you have to be sure that you r putting zero shear wall...!

Sushil