This book presents a new method of asymptotic analysis of boundary-layer problems, the Successive Complementary Expansion Method (SCEM). The first part is devoted to a general presentation of the tools of asymptotic analysis. It gives the keys to understand a boundary-layer problem and explains the methods to construct an approximation. The second part is devoted to SCEM and its applications in fluid mechanics, including external and internal flows.

to Singular Perturbation Problems.- Boundary Layer Structure.- Asymptotic Expansions.- Successive Complementary Expansion Method.- Ordinary Differential Equations.- High Reynolds Number Flows.- Interactive Boundary Layer.- Applications of Interactive Boundary Layer Models.- Regular Forms of Interactive Boundary Layer.- Turbulent Boundary Layer.- Channel Flow.- Conclusion.