Effect of mainstream air velocity on velocity profile over a rough flat surface

In turbulent flow, the boundary layer is defined as the thin region on the surface of a body in which viscous effects are important. The boundary layer allows the fluid to stick at the surface and thus having the velocity of the surface and to increase towards the mainstream. Roughness is a component of surface texture. It is quantified by the vertical deviations of a real surface from its ideal form. To study the variations of velocity profiles at boundary layer and their influences especially in turbulence zone, the approaches were done.