Boundary Layer Theory

•  Boundary layer concept was given by L. Prandtl (Father of Fluid Mechanics)
• Boundary layer thickness is defined as the distance from the boundary where velocity at a distance y from the surface(u) is approximately equal to the free stream velocity(U)
• Three mathematical expression were derived namely
•    (a) Displacement Thickness
•    (b) Momentum Thickness
•    (c) Energy Thickness
• shape factor is the ratio of displacement thickness to  momentum thickness