[Ballistics_Sim]

Alright FOAMer's I have a question for you.

Lets assume you have a double-acting hydraulic cylinder. The piston completely seals and therefore you have two fluid regions. The actual motion of the piston is determined by the pressure differential between the two regions.

How does one set up a case like this?

Clearly one will require a moving mesh and a ____DyMFoam solver but how does one set up the boundry conditions, the dynamicMeshDict and the pointMotionUx to solve for the mesh motion and therefore the actual piston motion?

I was working through the movingCone tutorial case but the dynamicMeshDict and pointMotionUx files use a prescribed, constant velocity.

As far as base mesh is concerned, I believe that blockMesh is perfectly sufficient by taking advantage of the wedge patch type. Let me know if this is not the case. Essentially two blocks will be used, with a chunk taken out in the middle and allowed to move, to show the geometry and motion of the solid piston.

The end goal is to show a reservioir, cylinder and piston as the piston moves down the cylinder. Pressures on both faces of the piston are of interest as well as the velocity in the fluid. In other words: a finite volume of high a pressure fluid will push a piston in the +x from one side until the pressure on the other side is in equilibrium.

It seems fairly bizarre to me that there isn't a tutorial for this, since its a fairly common engineering application of CFD. Perhaps there is a whitepaper or someone who is more familiar with OpenFOAM.