FLUID MECHANICS TUTORIAL No. 3 BOUNDARY LAYER THEORY.
Figure 4 Boundary Layer along a Airfoil body. The boundary layer tends to separate from the walls, if the adverse pressure gradient is high. The boundary layer remains attached over the complete lower surface of the airfoil, but it separates someplace near the rear potion of the upper surface.
But before that let us refresh the concept of boundary layer especially turbulent boundary layer. Boundary layer theory In a flow bounded by a wall, different scales and physical processes are dominant in the inner portion near the wall, and the outer portion approaching the free stream.
The concept of a boundary layer and the term itself were introduced by L. Prandtl (1904) in connection with the solution of a boundary value problem for non-linear partial differential equations in the hydrodynamics of viscous liquids. The needs of aviation have led to the development of a boundary-layer theory in aerohydrodynamics.
The boundary layer (BL) is a relatively thin layer of fluid close to the surface of a body that is immersed in a flow of fluid. The grey-part in the image above shows the BL, where the velocity in the main-flow (freestream) direction increases fro.
The subjects cover laminar, transitional and turbulent boundary layers for two- and three-dimensional incompressible and compressible flows. The viscous-inviscid coupling between the boundary layer and the inviscid flow is also addressed. The book has a large number of homework problems.
I've a question regarding the definition of the velocity boundary layer. The boundary layer is defined (correct if I'm wrong) as the region close to the body where viscous effects are important and cause gradient of velocity from 0 (non-slip) at the surface to the free stream.
Boundary-Layer Theory Hermann Schlichting, Klaus Gersten This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics).