[CBranch171]

Hi, I'm look for any openfoam example that uses activePressureForceBaffleVelocity as a boundary condition. I understand it requires two cycle patches but I struggling to see this implemented anywhere.

I would like to use this for modelling a bursting disk. So when the pressure gets to a certain value the baffle opens and allows flow into the downstream domain from master to slave.

I currently have an example that uses a pressure jump for an actuator disk would this serve as a basis and I substitute the activePressureForceBaffleVelocity BC. I basically want to make sure I have all the correct syntax.

[Tobi]

Still interested or almost over?

[CBranch171]

Hi yes I’m still interested in getting a working example on this

Thanks

[Tobi]

Hey,

I am working on a new tutorial that I will publish on my website. The aim is to simulate a vessel which does have a valve that opens after a defined pressure difference is reached (such as a rapture disc or safety valve). An impression is given below.




However for a first idea it is as follows:

• Create your geometry (here the tank)
• Use topoSet to create a face set. The face set includes all faces that are representing the rapture disc (or a valve or anything else). One can also add it to the snappyHexMeshDict to get a correct surface representation. However, the faces should be selected using topoSet
• Convert the face set into a faceZone (also done in topoSet)
• Use createBaffles to quadroplicate (nice word) the faces
  • a couple of cyclic patches
  • a couple of wall patches
• Use createPatch to merge the walls into one patch (checkMesh will throw an error but its okay)
• You are ready to go » for U apply the boundary condition on the merged wall patch and set the cyclic to the corresponding name

That's it.
If its to complicated, I will upload the case probably during the case.

[Tobi]

Hey,

I finished the case and published it on my website. Enjoy.

Tobi

[CBranch171]

Thanks I will go through it

Much apresciated.

[CBranch171]

Hi Tobi

I am still working on this problem. I am using openfoam 10 and you have used openfoam 2112. Is there a reason for you switching to openfoam 2112. I cannot get this to work, i.e. create the 4 required patches with openfoam 10. I just post a question on this.

[Tobi]

I am working within the team of ESI-OpenCFD, hence, I am involved into the developments here and also know whats released and whats going on

Thats why I used v2112.

[CBranch171]

Perfect. Nice to know why the change occurred. I can confirm 2206 is working and I get my cyclic patches and walls. Next step is to add the boundary condition.

[Tobi]

Yes, because my patch was added to v2206.

[CBranch171]

Hi Toby

I am using twoPhaseEulerFoam and have U.gas and U.water field. In your example you only have single U field. Do I apply the activePressureForceBaffleVelocity to each field so define it twice and do I need double the cyclic patches now.

i.e. you had 4 - 2 cyclic and 2 walls for a single U field

do I need 8 - gas (2 cyclic and 2 walls) and water (2 cyclic and 2 walls)

or can I use the same patches in the U.gas and U.water bc.

Thanks