[Joachim]

Hello everyone!

My question of the day: If you have a finite volume code, and you want to run a channel flow case, how do you drive the flow?

I am slightly confused, because even if I do not impose any pressure gradient, the flow will just keep on moving due to the periodic boundary conditions (no mass or momentum is being destroyed, so it has to keep on moving).

Basically, does the following procedure work?

1. compute the average flow rate
2. compute the delta flow rate = actual - target
3. define dpdx = delta flow rate/channel area
4. add dpdx as a source term in the momentum equation and rho*u*dpdx as a source term in the energy equation.

Is that ok? I am confused because I would have thought that my simulation would converge towards the pressure gradient required to drive the flow. Instead, following the previous procedure, the simulation will converge to the correct flow rate when dpdx goes to zero. Does that make sense?

Thanks!

Joachim