Direct and inverse integral calculation methods for three-dimensional turbulent boundary layers

Integral methods applied to compressible turbulent boundary layers encountered in aerodynamic design problems are reviewed. Prediction methods comprise finite difference techniques and numerical solutions and integral methods wherein ordinary differential equations obtained from partial differential equations integrated normal to the surface are solved numerically. Both methods involve streamlines and zones within and outside the turbulent boundary layer. Viscid-inviscid interactions require a change in the boundary conditions in order to model the effects on the boundary layer induced by the external flow. Approximate methods usually involve defining a velocity profile and marching methods of solution. Adding a lag entrainment term permits the application of inverse integral techniques. Sample theoretical and experimental results are presented for an infinite yawed wing.