[davide]

Hello everyone,

I am new to OpenFoam and I would like to simulate an unsteady model that requires moving boundary/mesh motion analysis.

However, the motion of the mesh nodes are already prescribed (known) as a function of time. so I do not need to use any dynamic mesh solver to calculate the position of each node.

Is it possible in OpenFoam to manipulate the position of each mesh node inside the domain as a function of time?

I appreciate if someone would help me with this issue.

Thanks
D

[kmooney]

Hi D,

You can do something like this to manipulate the mesh point locations as you like. You will need to incorporate this CV motion into your solver though relative/abs flux treatments.

Uniform mesh point manipulation can be quite easy:

        vectorField delCentroid(mesh.points().size(), deltaC);

        vectorField newPoints = mesh.points() + delCentroid;

        mesh.movePoints(newPoints);

Here I'm moving the mesh every timestep by a vector deltaC. You could loop through the motion vectors in 'newPoints' and move them independently if you wanted.

I hope that helps you out a bit.

Cheers!
Kyle

[davide]

Hey Kyle,

Thanks for the reply.

I will give it a shot and let you know the results.

Thanks
D

[immortality]

hello
I have the same problem.where in solver i should add this code?
Thank you.

[j-avdeev]

Hello.
If someone still interested.

	vector deltaC; 
	deltaC.x() = 0.01;
	deltaC.y() = 0.01;
	deltaC.z() = 0.01;
	
	vectorField delCentroid(mesh.points().size(), deltaC);
	forAll(mesh.points(),i)
	{
            Info << "mesh.points() " << mesh.points()[i] << nl << endl;
	}

        vectorField newPoints = mesh.points() + delCentroid;
        mesh.movePoints(newPoints);

        runTime.write();

This example moves whole mesh on (0.01; 0.01; 0.01) every timestep. It is probably useless, but it showes how mesh.movePoints() works.

[Clarkyan]

Originally Posted by j-avdeev

Hello.
If someone still interested.

	vector deltaC; 
	deltaC.x() = 0.01;
	deltaC.y() = 0.01;
	deltaC.z() = 0.01;
	
	vectorField delCentroid(mesh.points().size(), deltaC);
	forAll(mesh.points(),i)
	{
            Info << "mesh.points() " << mesh.points()[i] << nl << endl;
	}

        vectorField newPoints = mesh.points() + delCentroid;
        mesh.movePoints(newPoints);

        runTime.write();

This example moves whole mesh on (0.01; 0.01; 0.01) every timestep. It is probably useless, but it showes how mesh.movePoints() works.

Hi Avdeev,

Thank you for your code. I was wondering if you can indicate where we can add this type of code to? The source code of a solver like "displacementLaplacian" or a motion type like "oscillatingDisplacement"?

Thanks,
Clark

[khalid302]

Originally Posted by kmooney

Hi D,

You can do something like this to manipulate the mesh point locations as you like. You will need to incorporate this CV motion into your solver though relative/abs flux treatments.

Uniform mesh point manipulation can be quite easy:

        vectorField delCentroid(mesh.points().size(), deltaC);

        vectorField newPoints = mesh.points() + delCentroid;

        mesh.movePoints(newPoints);

Here I'm moving the mesh every timestep by a vector deltaC. You could loop through the motion vectors in 'newPoints' and move them independently if you wanted.

I hope that helps you out a bit.

Cheers!
Kyle

Hello Kyle,


I tried the code that you posted and got the following error:


--> FOAM FATAL ERROR:
V0 is not available

From function fvMesh::V0() const
in file fvMesh/fvMeshGeometry.C at line 382.

Any help would be appreciated.

Thanks,
Khalid