[reza.kaveh26]

Hi

I want model moving object (solid cylinder) fits in pipe and moves with pressure of fluid .first i want to know how do i sketch this model in2D in gambit or ANSYS design modeler (small rectangle moves in bigger rectangle).what are boundaries conditions specially between top &down walls of two rectangles (how can i define friction between them in ANSYS fluent )

and then how can i force smaller rectangle move with fluid's pressure in bigger rectangle.
Thanks