[rezasalehi]

Hello
I simulate solid particles in a two-dimensional rotating cylinder with the eulerian model.
The volume volume is logical, but the solid phase velocity constants show the velocity of solid particles in free space. Where there is absolutely air (in this space, the velocity of the solid phase should be zero); since the solid volume fraction shows the space above the solid bed empty of solid particles Gives.
Can anyone help me?
Why is it in the space above the bed that there are no solid particles but the speed contour shows the velocity of solid particles?