[riri_thegogoat]

Hi all!

I have a quite tricky problem related to the Dynamic Mesh Metod available in ANSYS Fluent.

I'm working on this "task" since 2 months, but I still have to solve one problem with my Dyn Mesh.

I have to simulate the opening and closing of an injector (I have a profile .prof that prescribes the movement of the rigid body - needle) with the smoothing and remeshing methods (NO LAYERING).

The main problem is the gap between the body of the injector and the needle: the gap between the two grows, so there I need new cells.

I start with a quite good mesh (tetrahedral elements due to the remeshing) with a gap of 10µm. Here I have the 5-10 layers each wall + 1-2 layers of cells between them.

When I go to ANSYS Fluent, I split my mesh in different zones in order to give them a movement/deformation/... Everything works, except the BL in the gap: it does not grow as I'm expected.

In the pics, there is the result for a spring coeff = 0 (the BL can only smooth and not remesh). If the spring coeff = 1, the BL on the other side has this behavior.

I also have some problems in the zone where the conical and cyilindrical parts of the needle get in contact: generally, they collapse. At the moment I'm moving the BL of the cylindrical part of the needle with a rigid movement, but there the BL will always remain super small and it's not a good solution.

If someone of you have an idea of how to solve this problem, I'd be the happiest person in the CFD World

Thanks

Arianna