Can anybody please tell me what type of mesh(2-D) i should use near the walls in a confined flow.(Wall bounded).The geometry consists of, a nozzle placed concentrically inside a large pipe.

Hi,

If u are solving viscous flow, near the to capture the boundary layer properly near the wall cartesian meshes are most suitable. as u have derivates in the direction perpendicular to the wall, u can have lo aspect ratio for these cartesian meshes and can capture the derivatives near the wall.Cartesian meshes are easy to refine and even if the aspect ratio is too high it doesnt matter. only near the wall