How to define surface roughness for motion simulation?

Hi all,

I hope someone can help me.

I have a cylinder liner where a piston (with piston rings) is moving up and down.

Cylinder liners have a honed surface (Ra 4 - 8 µm). I have three different honing types and I want to identify the friction force with the motion simulation.

I really do not know how to define the roughness of the surface.

Regards

Valerie

SolidworksMotion Studies