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PLIC-VOF with a Conservative formulation at high density ratio |
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#1 |
New Member
Abhishek
Join Date: Feb 2018
Posts: 4
Rep Power: 8 ![]() |
Greetings!
I am trying to develop a Two Phase VOF solver with a conservative formulation. I have successfully implemented the following:
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#2 |
Member
Join Date: Dec 2012
Posts: 92
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Basically what you have to do is not to use the average density for the interface density in the mass flux. Rather use a mass flux, which is calculated from the mass fluxes of the two phases:
if the face densities for the two phases are ![]() ![]() ![]() ![]() ![]() Now, the volume flux for the second phase ![]() ![]() Now just use these two volume fluxes to calculate the mass flux using the density for the two phases on the face seperately: ![]() This procedure worked very well for me. I can't give you a reference though, because I kind of came up with it myself. However, I am fairly sure someone has done and published it before. Last edited by beer; February 9, 2018 at 10:27. |
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#3 |
New Member
Abhishek
Join Date: Feb 2018
Posts: 4
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Hello! Thanks for the reply. Are you suggesting that the density at the faces should be calculated using the amount of both fluids present in the volume (face velocity*dt)*A?
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#4 |
Member
Join Date: Dec 2012
Posts: 92
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No, sorry I should have stated that. You should calculate the face density for each phase seperately. I edited my answer above.
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#5 |
New Member
Abhishek
Join Date: Feb 2018
Posts: 4
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Sorry but i still dont get what you are trying to say. Where do i need to use the mass flux?
Last edited by abhishek13; February 13, 2018 at 02:46. |
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#6 |
New Member
Nikhil
Join Date: Mar 2016
Location: India
Posts: 15
Rep Power: 10 ![]() |
Dear Abhishek,
This is caused due to disparity in Gamma (specific heat ratio calculation) Please refer the following paper, https://www.sciencedirect.com/scienc...21999115005021 titled "Preventing numerical oscillations in the flux-split based finite difference method for compressible flows with discontinuities". As this paper is highly condensed you might have to cross refer the references for more details. Regards, |
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#7 |
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Posts: 92
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#8 |
Senior Member
Saideep
Join Date: Apr 2015
Location: INDIA
Posts: 203
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Might be of use. A simple way is to filter the volume fraction several times so that you dont see a sharp jump in the fluid properties but a gradual jump. This is something that the software "Gerris Flow Solver" using PLIC-VOF does.
However, I did find that for some density ratios (air water) keeping the viscosity ratio as 1, the solver really struggles. |
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Tags |
conservative form, twophase fluid, volume of fluid |
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