[cyw]

Dear Foamers,

Does anybody implement level set method into compressibleInterFoam? Could you please tell me some theory guide?

Best Regards
CYW

[Taataa]

I have been working on it in my free time so I haven't had a significant progress yet.

Here is a good starting point. Look for "Coupled Level-Set with VOF interFoam, Sankar Menon (2014)" in the link and you can find the report as well as the files.

[cyw]

Originally Posted by Taataa

I have been working on it in my free time so I haven't had a significant progress yet.

Here is a good starting point. Look for "Coupled Level-Set with VOF interFoam, Sankar Menon (2014)" in the link and you can find the report as well as the files.

Thank you. I have tried what you said. But for compressibleInterFoam, I think it is different. I tried to implement level set in compressibleInterFoam, but the result it not good as the interFoam. The parasitic currents become more obvious...

[Taataa]

I will resume the work next month, will let you know if I have any achievement in this regard and if interested we can work together.

[cyw]

Originally Posted by Taataa

I will resume the work next month, will let you know if I have any achievement in this regard and if interested we can work together.

Thank you, but I cannot wait until next month...I have to do it right now

[Taataa]

Sorry, I've got my hands full this month. If you have any success please let me know. If you have any specific errors regarding implementation also maybe I can help.

[cyw]

Originally Posted by Taataa

Sorry, I've got my hands full this month. If you have any success please let me know. If you have any specific errors regarding implementation also maybe I can help.

No problem. I am simulating a bubble in still water without gravity. For interFoam and sclsVOFFoam, the result is OK and the parasitic current can be controlled. But for the compressibleInterFoam and sclsVOF_compressible, the result is not OK. The parasitic currents exist. Coupled level set method can not solve this problem. I am not sure if the method or my programming is wrong.

[Taataa]

Parasitic currents are a result of the way surface tension is implemented in OF so you have pay extra attention to the way compressibleInterFoam deals with surface tension modeling as it is different than interFoam. So implementing LS is not as straight forward as interFoam.

[cyw]

Originally Posted by Taataa

Parasitic currents are a result of the way surface tension is implemented in OF so you have pay extra attention to the way compressibleInterFoam deals with surface tension modeling as it is different than interFoam. So implementing LS is not as straight forward as interFoam.

Thank you for your information. I think they are the same. In compressibleInterFoam, the surface tension is calculated in interfaceProperties, which is the same in interFoam. And the surface tension is needed in UEqn.H,
which is interface.surfaceTensionForce().

[Taataa]

In case of a quiescent flow without gravity, lack of balance in surface tension and pressure gradient forces, and errors in curvature calculations is the source of the currents.

So I would suggest to look into this case and see how compressibility makes a difference in this simple case. At least that's what I was trying to do and understand. Just put a square bubble in a domain where the boundaries are 4 times the radius away from the bubble, remove the gravity and try it with the models that you have and figure out what are the differences.

[cyw]

Originally Posted by Taataa

In case of a quiescent flow without gravity, lack of balance in surface tension and pressure gradient forces, and errors in curvature calculations is the source of the currents.

So I would suggest to look into this case and see how compressibility makes a difference in this simple case. At least that's what I was trying to do and understand. Just put a square bubble in a domain where the boundaries are 4 times the radius away from the bubble, remove the gravity and try it with the models that you have and figure out what are the differences.

Thank you for your information. I have simulating a case similar to you without gravity. The parasitic current exists for the result from compressibleInterFoam and also for that coupled with level set method. I doubt where I am wrong or the compressibleInterFoam coupled with level set cannot solve this parasitic current...

[Taataa]

I see.
In general I don't think coupling with LS provide a significant advantages in this case, otherwise they would have implemented it officially. The CIF solver is complex, adding more complexity wouldn't help I suppose.
There are some alternatives though. If you need sharp interface you can try using isoAdvector solver. It's already a part of OF v1706, here.
There are some nice comparison between interFoam and CLSVOF in this paper. interFoam performs very well.
Also, you can try implementing a force balancing algorithm which are specifically for this purpose, for example this paper.

[cyw]

Have you simulated the dambreak case in the tutorial with sclsVOFFoam? What is the result?
In the report, the sclsVOFFoam can only handle zerogradient boundary condionts? What does that mean? How to handle other boundary conditions?

[ArminAlavi]

Originally Posted by cyw

Have you simulated the dambreak case in the tutorial with sclsVOFFoam? What is the result?
In the report, the sclsVOFFoam can only handle zerogradient boundary condionts? What does that mean? How to handle other boundary conditions?

Hello Yuanwei
Did you manage to find out how to handle other boundary conditions in the sclsVOFFoam solver?