[Furkanenes76]

Hello everyone,

I was trying to simulate hydraulic piston-cylinder assembly in ANSYS Fluent. I form a 2D geometry. I use triangular meshes to activate remeshing. Then, the dynamic mesh is opened in the Fluent interface and Sixdof is activated. There is a simple pressure inlet and pressure outlet so the piston goes to the outlet side. My question is that when I did not change air properties, the problem was solved correctly and converged at every step. However, when I define my oil properties, it starts to show unbelievable pressure values at the start of the calculation and then the solution diverges (Although in initialization everything seems OK in terms of pressures). I really do not understand. What can be the reason for this? By the way, the problem is with density. The change in viscosity does not lead to divergence.
Does anyone have an idea? I will be glad if anyone can help me.

Regards.