[Saeid]

Hello to all,

I run a lot of models about simple friction test.

I have 1 cube in my model with this informationall SI unit)
dimensions: 0.5*0.5*0.5
mass density: 2000
collision properties: Coefficient of friction=0.5 & Coefficient of restitution=0.9.
Type of moving object: Coupled Motion(all velocity = 0 , z displacement in negative direction = 0 , 6 Degree of freedom)

and behind of this cube, there is a fluid regime with 6 m length and 0.5 m height(water) (initial velocity=0 and pressure distribution is Hydro-static).

just this.

after I run the model, the cube start to move!!! this is my problem!!
as I know about equilibrium equation for this simple test, the cube must not move, but it move.

please help me if possible.

[Saeid]

No one can help me?