backward facing step simple with no particle
 

hi.im trying to find a good article about backward facing step meshing and i want to valid my work with it in reattachment point after step.and another ask is that for back ward facing step which mesh is good . is there any refrence or toturial for it.when i choose ratio for my mesh it creat a bad diffrence between the size of that part and the mesh for another part
help me
in one sentences help me for having a smooth mesh.tnx:)