[vigges]

Hello Foamers!

I'm trying to simulate a non-submerged oil jet impingement on a flat plate with compressibleInterFoam. As turbulence model, kOmegaSST is used. It's a 2D axisymmetric problem, so I use cyclic boundary conditions on the FRONT and BACK patch. As shown in the attached sketch, I initialize the upper reservoir so that it is filled with oil which has a velocity Uy = -0.7 m/s which corresponds to the volumetric flow rate specified by the flowRateInletVelocity boundary condition. The other boundary conditions are defined as follows:

inlet:
U | flowRateInletVelocity
p_rgh | zeroGradient
p | calculated
T | fixedValue
k | turbulentIntensityKineticEnergyInlet
omega | compressible::turbulentMixingLengthFrequencyInlet

outlet:
U | zeroGradient
p_rgh | fixedFluxPressure
p | calculated
T | zeroGradient
k | zeroGradient
omega | zeroGradient

walls & bottom:
U | zeroGradient
p_rgh | fixedFluxPressure
p | calculated
T | fixedValue
k | fixedValue
omega | compressible::omegaWallFunction;

Well, after hours of simulation, I was glad seeing the oil phase flowing almost as expected. When looking at the velocity & k distributions, there are regions of high values outside oil jet which I did not expect. The region of high k values more or less stays at the same position over several time steps, the region of high velocity is moving up and down periodically.

I was wondering if it has someting to do with my boundary conditions. Maybe somebody has experience with something like that. Before I start 'playing' around with the fvSchemes file, I'd like to make sure it's not something more easier to fix ;-)

Thank you :)

[olivierG]

hello,

You set a zeroGradient for the outlet velocity. This is clearly not true here. So
- extend the outlet enough that the zeroGradient is ok.
- try another BC: inletOutlet, ...

regards,
olivier

[Andres_Aguirre3]

Dude, I am trying to model a similar case, I am using compressibleInterForam as turbulent flow (KomegaSST) and I have a lot of problems and errors and I think I am incorrectly constructing the "FvSolution and FvSchemes" files.

Do you think you can share your case to guide me or help me with these two files to know how to place them correctly?

Thank you.