|July 24, 2013, 08:39||
[twoPhaseEulerFoam] Difference in drag models
Join Date: Aug 2009
Posts: 24Rep Power: 9
I am modeling a water-solid flow using twoPhaseEulerFoam and would like to discuss some issues regarding drag models with you.
After struggling a bit with some non-physical results, I have decided to run the simplest test I could think of: settling particles.
The description of the system is:
- 2D (1 element in z) 0.20 x 0.60 x 0.01 - uniform mesh with 3 mm x 3 mm elements.
- Water + particles (3 g/cm3, 100 micra)
- Initial condition: uniform - zero velocity, solid volume fraction 0.21.
- No turbulence
- ppPArticle g0 = 0
- kinetic theory = off
(so basically, the model ignores particle-particle interactions)
The test: GidaspowErgunWenYu drag model x SchillerNaumann drag model
I have allowed the particles to settle for 300s (timestep around 0.01s, Courant under 0.5).
Results (see pics):
- Using GidaspowErgunWenYu absolutely nothing has happened. The particles didn't settle, nothing.
- Using SchillerNaumann, the particles settled and after a while some strange flow in the bottom (which was expected because the lack of a model for accounting for particle-particle interactions at high solid volume fraction).
I have tested also using the GidaspowErgunWenYu model with a higher solid volume fraction (0.40, the rest of parameters unchanged) and got the same result (no settling).
Do you have any thoughts about this? Is this expected for GidaspowErgunWenYu?
ps: i am uploading the pics in two batches
|December 16, 2013, 07:37||
Join Date: Oct 2012
Location: Lappeenranta, Finland
Posts: 682Rep Power: 15
Have you tested your model with Kinetic theory? If so did you notice any changes in the results.
|October 6, 2014, 15:08||
Join Date: Sep 2009
Posts: 10Rep Power: 9
Please find attached a case with your specifications that was run with GidaspowErgunWenYu drag model. Settling was obtained in this case.
OpenFOAM V.2.2.1 was used on OS Ubuntu 12.04.
|drag coefficient, euler-euler, multiphase, openfoam, twophaseeulerfoam|
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