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help! VOF method in OpenFOAM

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Old   October 19, 2016, 05:29
Smile help! VOF method in OpenFOAM
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OpenFOAM is excellent on the simulating single phase flows. However, the VOF method in OpenFOAM is doubted by lacking one important step: ‘free-surface reconstruction.’ The VOF method is ideal for studying the wave dynamics. It includes two major steps: 1. Re-distribute fluid mass based on the VOF equation. 2. Reconstruct the free-surface for accurately estimating the volume flux on each cell face. The first step was included in the OpenFOAM. However, the second one is not. It results on the smoke-like breaking waves in OpenFOAM. Anyone konw how to slove it? Please shall your address.

Last edited by liuxiaojian2015; October 19, 2016 at 08:34.
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Old   October 19, 2016, 16:14
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Hi Liu,

Interfoam solver in Openfoam is a Pseudo VOF method which is different from Geometrical VOF methods like PLIC. In interfoam, solving the governing equation for vof (which includes an additional interface compression term) is another alternative to the geometrical method which includes reconstruction and advection.

Try refining the mesh, changing the Courant number may be it helps a little
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Old   October 20, 2016, 00:40
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Quote:
Originally Posted by vigneshTG View Post
Hi Liu,

Interfoam solver in Openfoam is a Pseudo VOF method which is different from Geometrical VOF methods like PLIC. In interfoam, solving the governing equation for vof (which includes an additional interface compression term) is another alternative to the geometrical method which includes reconstruction and advection.

Try refining the mesh, changing the Courant number may be it helps a little
Hi Vignesh,

Thank you very much for your reply. Meanwhile, thank you for your help and valuable advises. Though try refining the mesh, the phenomenon of smoke-like breaking waves still exist when amplify the free surface. Because the reconstruction of free-surface was not included in the OpenFOAM by using the MULES scheme on the simulating two phase flows. Do you know other method included in the OpenFOAM can slove the phenomenon of smoke-like breaking waves.

Enjoy,


Xiaojian Liu
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Old   October 20, 2016, 03:24
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Quote:
Originally Posted by liuxiaojian2015 View Post
Hi Vignesh,

Thank you very much for your reply. Meanwhile, thank you for your help and valuable advises. Though try refining the mesh, the phenomenon of smoke-like breaking waves still exist when amplify the free surface. Because the reconstruction of free-surface was not included in the OpenFOAM by using the MULES scheme on the simulating two phase flows. Do you know other method included in the OpenFOAM can slove the phenomenon of smoke-like breaking waves.

Enjoy,


Xiaojian Liu
Hi Liu,

Try to explain your problem in detail (showing some snapshots of interface and your mesh size, solver settings) there might be some one who could help you.

check this thread
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Old   March 13, 2018, 00:08
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This is the result of smoke-like breaking waves! Anyone is welcomed to discuss it. Thanks.
Attached Images
File Type: jpg wave runup.jpg (41.2 KB, 183 views)

Last edited by liuxiaojian2015; March 13, 2018 at 00:15. Reason: A error operation so that the picture can not be loaded
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Old   November 10, 2022, 05:50
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Even i get the unphysical interface when using interDyMFoam on circular cylinder with piston moving resulting in topochangnig simulations. Have you got rid of it? Putting max Co to 0.1 resuces but it doesnt eliminate the problem. Still open to share the solution.
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Old   November 18, 2022, 04:50
Default interIsoFoam instead of interFoam?
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Have you considered interIsoFoam. It is available in the ".com" version of OF, i.e. openfoam.com. I believe it has some kind of reconstruction phase.


P.s. For the interested, in the paper below, the two major VOF families are summarized in a short and clear manner, namely the direct methods and the reconstruction methods, see...

Analysis of shear rate inside a concrete truck mixer, Cement and Concrete Research, Vol. 95, 2017, pp 9-17.

https://www.sciencedirect.com/scienc...08884616310961



hope this helps
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Old   November 27, 2022, 23:57
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With layer addition/removal for topologically changing meshes, I guess I have to make changes to the base iso advector interface capturing scheme. Hope it comes out for foam extend.
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Old   February 1, 2023, 04:46
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The wave has oscillations. Simply refining the mesh actually makes the computation longer without much improvement in the results. It occurs specially when the wave run up becomes higher. 1 second and 1.42 seconds pictures are attached for reference of the problem.
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File Type: jpg 1.42s flow.jpg (28.6 KB, 30 views)
File Type: jpg 1s flow.jpg (29.2 KB, 24 views)
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