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kornickel November 5, 2013 17:51

General setup of turbomachinery cases
Hi everyone,

I am currently trying to run a turbomachinery case with not very much information about. It is an axial fan inside a bis tube and I want to calculate the volume flow at the inlet/outlet and the resulting pressure at the inlet. I also did the MRF setup.

I do have the mesh (geometry), I know the outlet pressure, the rotating speed of the fan, temperature and the data of the fluid (air).

I want to run it incompressible, so I've chosen simpleFoam with turbulence model Standard k-Epsilon.

My settings in the "0" folder are for the U field:

- internalField: (0 0 0)
- at the walls/fan blade: fixedValue (0 0 0)
- at the inlet: pressureInletVelocity
- at the outlet: inletOutlet

for the p field:

- internalField: 0
- at the walls/fan blade: zeroGradient
- at the outlet: fixedValue 0

but what to chose as inlet type and value? Can I also use zeroGradient at the inlet?

for the nut field:

- internalField: 0
- at the walls/fan blade: nutkWallFunction
- at inlet/outlet: calculated

for the k and epsilon fields:

- at the walls/fan blade: kqRWallFunction and epsilonWallFunction

and here again, what to chose as inlet and outlet values/types, since I don't know the flow speed and cannot estimate approximate values of k and epsilon?

For the internalField of k and epsilon I would chose the value 0 since the flow at time 0 is 0 as well.

Best regards,

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