Channel Boundary Condition

FlyBob91 · October 18, 2016, 11:44

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 · October 19, 2016, 10:06

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).

October 18, 2016, 11:44	Channel Boundary Condition	#1
FlyBob91 Senior Member Join Date: Mar 2016 Location: Bergamo Posts: 157 Rep Power: 10	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

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October 19, 2016, 10:06		#2
agustinvo Senior Member Agustín Villa Join Date: Apr 2013 Location: Alcorcón Posts: 314 Rep Power: 15	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).