[FloatingSolar]

Hey everyone,

I am trying to simulate multiple floating objects in a multiphase environment (air, water, and solid structures) with 4 DoF (3 DoF rotation, and 1 DoF translation in z-direction) in OpenFOAM version 5 in order to study the orientation of the floating objects when being subjected to waves.

I have succeeded in using interDyMFoam and the sixDoFRigidBodyMotion solver to simulate a single floatingObject (with these 4 DoF), which seems to work fine. I keep getting stuck when adding a second object though. I have tried a couple of different approaches:

1. Simply 'adding' a second floater in all files used by the original floater (dynamicMeshDict, blockMeshDict and all of the files in the '0' folder), adding a second topoSetDict file, and expanding the Allrun file to create two subsetMeshes. The solver runs for this, but the floaters seem to be ignored and it simulates just the water and the air.

2. Switching to a displacementLaplacian solver with inverseDistance for the diffusivity, defining the two floating objects (and all their parameters) in the pointDisplacement file, and using the sixDoFRigidBodyDisplacement as a patch for the floating objects. This gives me the "unknown patchField type sixDoFRigidBodyDisplacement for patch type wall" error. There is however no other sixDoF patchField type which is valid. Is there any way I can keep using the same patchField?

3. Switching to the rigidBodyMotion solver allows me to add a second floating object. This gave me a couple of new problems though.
- The floating objects are extremely unstable and immediately flip over, which ends the simulation.
- I can't seem to get a composite joint working which allows both 3DoF rotation (type Rxyz) as well as translation in z-direction (type Pz).

If anybody would be able to give me some advice or point me in the right direction, I would be very thankfull! Also, I would gladly upload any file which could help you understand my situation. I'm just not sure which files that might be, so feel free to let me know!

Kind regards,
Daan

[pvreis]

Originally Posted by FloatingSolar

Hey everyone,

I am trying to simulate multiple floating objects in a multiphase environment (air, water, and solid structures) with 4 DoF (3 DoF rotation, and 1 DoF translation in z-direction) in OpenFOAM version 5 in order to study the orientation of the floating objects when being subjected to waves.

I have succeeded in using interDyMFoam and the sixDoFRigidBodyMotion solver to simulate a single floatingObject (with these 4 DoF), which seems to work fine. I keep getting stuck when adding a second object though. I have tried a couple of different approaches:

1. Simply 'adding' a second floater in all files used by the original floater (dynamicMeshDict, blockMeshDict and all of the files in the '0' folder), adding a second topoSetDict file, and expanding the Allrun file to create two subsetMeshes. The solver runs for this, but the floaters seem to be ignored and it simulates just the water and the air.

2. Switching to a displacementLaplacian solver with inverseDistance for the diffusivity, defining the two floating objects (and all their parameters) in the pointDisplacement file, and using the sixDoFRigidBodyDisplacement as a patch for the floating objects. This gives me the "unknown patchField type sixDoFRigidBodyDisplacement for patch type wall" error. There is however no other sixDoF patchField type which is valid. Is there any way I can keep using the same patchField?

3. Switching to the rigidBodyMotion solver allows me to add a second floating object. This gave me a couple of new problems though.
- The floating objects are extremely unstable and immediately flip over, which ends the simulation.
- I can't seem to get a composite joint working which allows both 3DoF rotation (type Rxyz) as well as translation in z-direction (type Pz).

If anybody would be able to give me some advice or point me in the right direction, I would be very thankfull! Also, I would gladly upload any file which could help you understand my situation. I'm just not sure which files that might be, so feel free to let me know!

Kind regards,
Daan

Hey Daan,
Have you solved your problem?
I have a similar case, using twto bodies.
I tried your second case and I got the same errors.
Could you help me?
Thanks.

[FloatingSolar]

Dear Paulo,

Unfortunately I have not managed to solve this problem and ended up taking a completely different (not CFD related) approach to my project. So I'm sorry,but I can not help you with this.

Kind regards,
Daan

[Fluid Tool]

Dear Paulo and Dann,

1. I see in OF4 it has sixDoFRigidBodyDisplacement allowed user set 6dof for each patch.

https://github.com/OpenFOAM/OpenFOAM...dyDisplacement

You can use reference tutorial at here:

http://www.tfd.chalmers.se/~hani/kur...usUrquhart.pdf

2. From OF5 to latest version, it have been removed in BCs list, so you can not see it. I also want to run multi 6dof for multi patch. It may copy lib from OF4 to new OF and compile it.

[mostafa R]

Hi,

You can see my last post in the following thread:

Multiple Floating Objects with 6DoF in OF 2.3.0