Acrude approximation for the x component of velocity in an incompressible laminar boundary layer is a linear variation from u = 0 at the surface ðy = 0þ to the freestream velocity, u, at the bound- ary-layer edge ðy=δþ. the equation for the profile is u=uy=δ, where δ = cx1=2 and c is a constant. show that the simplest expression for the y component of velocity is υ = uy=4x. evaluate the maximum value of the ratio υ=u, at a location where x=0: 5m and δ=5mm.