[Belimane]

Hello,
i want to simulate the fluid flow through concentric pipes (as in the pic), at the outlet we have the pressure and at the inlet we have the total flow rate.
the problem is that we don't know the flow rate in the annular space and inside the pipe, but we do know that the pressure gradient in the two spaces is the same.
i want to know if it is possible to set an iterative calculation in Fluent so that during simulation, the flowrate will be updated at every step till the pressure gradient becomes almost equal (below an error).

[vinerm]

One way to do that is to use periodic condition. Make inlet and outlet periodic and then provide the pressure gradient in Periodic Conditions. If you do not want to use periodic condition, then merge both inlets into one and provide mass flow rate. Fluent will automatically divide the flow rate across two regions.