[jason]

Hi,

Just a general question, is there any attempts with OF at modelling free body dynamics coupled with fluid flow. For example, would it be possible to assess the movement of a wave power machine due to the passing of a wave? Or the rotation of a Tidal Turbine due to the passing of a tidal current. I'm not interested in the actual stresses in the solid component (well, not yet anyway!) just the action of the fluid forces on the structure. I have seen that Flow3D can do something like this and I have worked on the Phoenics MOFOR in the past. I'm not familiar with Flow3D but I know that with the Mofor you have to specify the movement beforehand, good for some things but not for this.

Would appreciate any info on the subject.

Many Thanks

Jason

[hjasak]

So basically what you need is:

- a fluid flow solver with support for moving meshes;
- force calculation on the boundary;
- a 6-DOF solver that can calculate the position/motion based on the forces and intertial parameters. This will determine the boundary motion for you;
- an automatic mesh motion solver, which will deform the mesh based on prescribed boundary motion.

OpenFOAM has got all four. Have a look at the FSI examples from the OpenFOAM Workshop; the 6-DOF solver is described in a separate presentation.

Enjoy,

Hrv

[jason]

Hi,

Thanks for the info, very interesting.

Jason

[nico765]

Hello,

The paper presenting the 6-DOF solver has a nice example at the end (oscillating cylinders). Was it run with something similar to MRFSimpleFoam?

Regards,
Nicolas

[paulchang]

Hi, are there any existing examples about the dynamic interaction between fluid and solid using FOAM?

Thanks for any info.

Paul

[hjasak]

Yes, lots. Have a look at my slides from two recent conferences:

MIT Fluid-structure OpenFOAM

ICCSM5 overview OpenFOAM

There are also papers and work by other groups (prof. Ivankovic, UC Dublin, Frank Bos, Uni Delft, D. Matijasevic, Uni Zagreb etc.) but I haven't got all this ready at hand.

Hrv

[francesco_b]

Hi Hrv,

you wrote:

So basically what you need is:

- a fluid flow solver with support for moving meshes;
- force calculation on the boundary;
- a 6-DOF solver that can calculate the position/motion based on the forces and intertial parameters. This will determine the boundary motion for you;
- an automatic mesh motion solver, which will deform the mesh based on prescribed boundary motion.

OpenFOAM has got all four. Have a look at the FSI examples from the OpenFOAM Workshop; the 6-DOF solver is described in a separate presentation.

Can you please tell me how I could put this things together? I'm quite new to OpenFOAM and C++, but I'm really interested in writing a solver with these characteristics. In your opinion what should I do to reach this aim? Can you please tell me the steps?

Thank you in advance

Francesco

[hjasak]

What you are asking for is free support, and I don't do that. There's plenty of examples and I've given you the material. If this is still to hard, please contact me directly and we can set up some sort of collaboration.

I'm sure you understand,

Hrv