[dasith0001]

Hi Foamers,

My problem is simple yet could not find an acceptable solution.

I have a relatively large cylinder pressurised with gas up to 200MPa and it has one relatively very small outlet exposed to atmospheric pressure.

Using the wedge domain I am trying to find out the rate of the pressure loss inside the cylinder. I am using rhoPimpleFoam V10

I have used following combinations of P and U so far

1. P - fixedPressure and
U - zeroGradient/inletoutlet/pressureInletOutletVelocity

(for this, solver is stable but time stepping is too small despite the meshing. practically insolvable with very small time steps.)



2. P - totalPressure and
U - zeroGradient/inletoutlet/pressureInletOutletVelocity

(for this, solver is stable but time stepping is too small despite the meshing. practically insolvable with very small time steps.)



3. P - waveTransmissive and
U - zeroGradient/inletoutlet/pressureInletOutletVelocity

(Currently working on this, time stepping is reasonable but I am not sure if waveTransmissive condition can mimic the venting scenario. depending on the Inf value pressure loss varies)

Any suggestion of P and U boundary conditions for this particular condition, is greatly appreciated. Thank you

Dasith