[FlyBob91]

Hello,
i have to run an unsteady simulation about a 3D channel using pimpleFoam and i have some doubts about the inlet and outlet boundary conditions.
The channel works at constant mass flow rate and, for this exercise, i have to impose a cyclic boundary conditions knowing the mass flow rate and the inlet velocity.
My exercise is a 3D channel similar to a nozzle.
Can someone explain me how do this and why we impose cyclic boundary condition?

Many Thanks

[agustinvo]

Hello,

I think there is a tutorial related with this, Re395, where you can see the setup of your case.

If you know your mass flow, you should take a look to the fvOptions file, where you can specify it, or specify the pressure gradient (I prefere this last one).