This is the first book in English devoted to the latest developments in fluid mechanics and aerodynamics. Written by the leading authors in the field, based at the renowned Central Aerohydrodynamic Institute in Moscow, it deals with viscous gas flow problems that arise from supersonic flows. These complex problems are central to the work of researchers and engineers dealing with new aircraft and turbomachinery development (jet engines, compressors and other turbine equipment). The book presents the latest asymptotical models, simplified Navier-Stokes equations and viscous-inviscid interaction theroies and will be of critical interest to researchers, engineers, academics and advanced graduate students in the areas of fluid mechanics, compressible flows, aerodynamics and aircraft design, applied mathematics and computational fluid dynamics.