[cfd kullanıcısı]

hello everybody.
I'm trying to analyze the gun barrel in fluent, but I haven't succeeded yet. firstly, I need to help about dynamic mesh. I try to use dynamic mesh (layering) but I cannot create dynamich mesh. How can I solve this problem? Secondly, I don't know how I can use boundry conditions. My goal is to find the recoil force. Can you help me?

Thank you for your answers..

[bloodflow]

Layered dynamic meshes require care named selection of the required interfaces. I am guessing you model looks something like: GAS A | Wall | GAS B, with solid walls all around the gas/bullets which is the gun barrel.

- Make sure your geometry has shared topology, and all the bodies are grouped into two parts (one for solids and one for fluids)

You need to create named selection for interfaces between the deforming walls of Gas A, and The Solid walls of the gun barrel. Name select the fluid wall of Gas A as (interface-gas-a-deforming) and the gun barrel as (interface-gun-barrel-inside). This process must be repeated everywhere a fluid zone wall is deforming alongside a solid wall which is stationary.

When done correctly, you can import the mesh into Fluent and ask it to 'Auto Create Interfaces'. This should give NO errors if done correctly. When you preview the zone motion, it often looks wrong, but this is because the mesh on the walls is fixed. Previewing the mesh motion should give the correct result (but save a case file first, you cant take the mesh back in time!)

Sebi