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Patching phase volume fractions for two adjacent bodies

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Old   September 7, 2022, 11:25
Default Patching phase volume fractions for two adjacent bodies
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Edmund
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I have a simulation with two solids sharing a contact face. There are three phases: a, b, and c. Phase a is the primary phase. Phase a comes through a mass-flow inlet and enters the solid containing phase b. There is a porous jump between the solids that contain phases b and c. There is a pressure outlet on the solid that contains phase c.

I patched the phase volume fractions in the cell zone containing phase b to 1 for phase b and 0 for phase c. For the cell zone containing phase c, I set the volume fractions to 0 for phase b and 1 for phase c. I have my other settings attached in a screenshot below. When doing this, I received the following error message:

Warning!! The sum of phase volume fractions exceeds 1 in some cell(s).
This can lead to potentially erroneous initialization. Please insure that the sum of phase
volume fractions in a cell does not exceed 1 during intitialization or patching!!

I thought "patch reconstructed interface" would prevent this error, but I guess not. Running the simulation resulted in contour plots with a constant volume fraction of zero for all phases.

I also tried running the simulation with only phases a and b. I set the volume fraction for b and c equal to zero for the solid originally containing phase c. This prevented the error, but resulted in the same contour plots.

Does anyone know how to fix the error or the contour plots?

Sorry for not including any additional screenshots, but I can't reveal the names of any of the substances used or the geometry of the simulation.
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File Type: png patch censored.PNG (41.8 KB, 21 views)
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Old   November 7, 2022, 06:49
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Abhinav Maurya
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I'm facing a similar issue, I hope anyone can help in this
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Old   December 13, 2022, 21:37
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Quote:
Originally Posted by elgato View Post
I have a simulation with two solids sharing a contact face. There are three phases: a, b, and c. Phase a is the primary phase. Phase a comes through a mass-flow inlet and enters the solid containing phase b. There is a porous jump between the solids that contain phases b and c. There is a pressure outlet on the solid that contains phase c.

I patched the phase volume fractions in the cell zone containing phase b to 1 for phase b and 0 for phase c. For the cell zone containing phase c, I set the volume fractions to 0 for phase b and 1 for phase c. I have my other settings attached in a screenshot below. When doing this, I received the following error message:

Warning!! The sum of phase volume fractions exceeds 1 in some cell(s).
This can lead to potentially erroneous initialization. Please insure that the sum of phase
volume fractions in a cell does not exceed 1 during intitialization or patching!!

I thought "patch reconstructed interface" would prevent this error, but I guess not. Running the simulation resulted in contour plots with a constant volume fraction of zero for all phases.

I also tried running the simulation with only phases a and b. I set the volume fraction for b and c equal to zero for the solid originally containing phase c. This prevented the error, but resulted in the same contour plots.

Does anyone know how to fix the error or the contour plots?

Sorry for not including any additional screenshots, but I can't reveal the names of any of the substances used or the geometry of the simulation.
What Multiphase model are you using?

Check what value you are patching for the phase listed during the initialization. If this phase is A, and initialized at 1 throughout the domain, and then you try and patch B as 1 the sum will be >100%.
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File Type: png PhasePatching.png (32.0 KB, 8 views)
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Old   December 13, 2022, 21:54
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Edmund
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I'm using the volume of fluid model. I believe I set the values for each correctly, but I can't test it as I've changed my simulation since I first posted this so it has only two phases. I still have this thread open in case anyone has the same problem (it looks like someone else did).
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