Approximate methods for a boundary layer on a flat plate with zero pressure gradient

In this section, the momentum integral equation (7.59) will be solved to give approximate expressions for the skin-friction drag and for the variation of 8, S*, в and Cf along a flat plate with laminar, turbulent and mixed laminar/ turbulent boundary layers. This may seem a rather artificial and restrictive case to study in depth. It should be noted, however, that these results can be used to provide rough, but reasonable, estimates for any streamlined body. The

equivalent flat plate for a specific streamlined body would have the same surface area and total streamwise length as the body. In this way reasonable estimates can be obtained, especially for the skin-friction drag, provided that the transition point is correctly located using the guidelines given at the end of Section 7.9.