[brightfame3]

Good afternoon.

I am simulating an IC Engine in fluent and I am having some issues with my results and i believe it is due to a problem with the deforming mesh. The issue in question is shown in the image. My problem is 3D, however I have posted the faces which are problematic in order to visualize easier. As you can see, there are two cells in particuar that keep on stretching and become very large and influence the rest of the surrounding cells. I have tried modifying the parameters of all deforming zones, but I have had no success. Any suggestions?

Thanks for your time! Greetings!

[vasava]

This could be because your moving boundary and stationary boundary are sharing those elements. If I am not wrong you may need some additional condition for that stationary face also. May be a fixed position. Also try with refined mesh so that there are no elements shared between moving and stationary walls.

[brightfame3]

Thanks for your reply! I was suspecting that the problem could be that. The white faced mesh is the deforming face which "grows" with the valve movement. The yellow faced mesh is a symmetry face which also deforms due to the valve movement. The other face that shares the same elements is a wall and I haven't defined anything to it. So, just to be sure, you are saying that I should define that wall as stationary? I was trying to avoid refining the mesh, since I will get a very large number of elements due to the size of my domain.

Greetings! And thanks once again!

[vasava]

Originally Posted by brightfame3

So, just to be sure, you are saying that I should define that wall as stationary?

By stationary I mean you fix its position of that wall. You could do this by use of DEFINE_GEOM macro. See following example where X-coordinate for a wall is fixed to 0.1.

DEFINE_GEOM(plane, domain, dt, position)
{
	position[1] = 0.1;
}

I have seen this in 'Oscillating Membrane' tutorial.

[brightfame3]

Thank you for the advice! I will give it a try and I will give a feedback if it did or not work. Thanks once again!