Hello,

Is the only way to change mesh files in a transient run through the use of a Junction Box Routine?

Thanks for your input.

Erich

Yes, but this can only be done if the mesh topology remains the same. If you want to run a transient where there is remeshing being done you will have to stop and restart the solver between meshes. This can usually be limited to a few key-meshes in a run, with mesh morphing handling the boundary motion in-between.

-CycLone

Thanks CycLone,

To what level will the mesh morphing usually go? Is this morphing defined only by mesh motion?

CycLone means that you cannot change the initial mesh, just carefully move their nodes without degenerate the volumes that they conform. (for example: overlap two or more nodes)

The mesh morphing can be pushed pretty far, but it will depend on what it is your doing. Motion can be defined at a boundary or expressions can be provided for the volume motion. The solver "diffuses" the motion through the rest of the mesh by solve a mesh diffusion equation, as opposed to using a spring analogy.

In general it can't handle the complete collapse of a portion of the mesh (i.e. a valve closing), but you could get close. In some cases you can also modify the geometry slightly, such as adding a small "seat" for the valve mesh to collapse into, and add sliding interface along the side so only the moving portion needs to be compressed.

-CycLone

One of the tutorials covers reading in different meshes through a junction box routine. I think # 20 or 21.

Thanks for all of your contributions. I have gone through the tutorials. The problem we have will need the topology to change and the mesh deformation would be quite severe. I am leaning towards an approximation per CycLone to produce a 'design' cycle CFD model to look at the big picture.

If the mesh cannot be mapped, then you cannot use a Junction Box routine. You will need to stop your run, and interpolate the results on to your new mesh.