Hi Everyone,
I am working on a model in which i want to simulate a full closed cycle (no inlet and no outlet) with a piston resulting in an oscillatory motion by pushing the fluid in the cylinder to pass through the rest of the components in the cycle back and forth.
i tried using the moving mesh (ALE) and i managed to move the piston -by defining sine equation for the displacement- and affect the adjoining mesh in the cylinder (with no effect on the rest of the mesh representing the other components).
the problem is that see that there is no coupling between the fluid and the mesh when i introduce the laminar flow physics although i tried the following: 1- i introduced 3 walls (slip walls for the cylinder walls, moving walls for the piston and non slip for the rest of the walls) i have given the moving walls the value (yt) to account for the velocity resulting from the moving mesh. result: i have got the error (Pointwise constraints for time derivatives are not supported). 2- i tried using the same but this time i define a cosine equation for the moving wall velocity. result: convergance problem.
i wonder if anyone can help me with this problem.