fluid flow through a rough channel
 

hi guys.

I want to model fluid flow through a rough channel. it's for a laminar incompressible flow. its geometry is like a cube, but its inner surfaces have roughness. roughness is like natural topographies and rock surfaces. one direction of the cube is the inlet, the other is the outlet and I want 3d modeling. geometry size is like 100*100*0.1 mm

which tutorials do you suggest? which way do you think is better for meshing? (Salome, snappyHexMesh, other meshing software)

https://postimg.cc/TpVdDQHG