Introduction to Compressible Flows

This chapter provides a brief introduction to compressible flows, including fundamentals, physical regimes, and associated flow phenomena. It introduces the notion of shock and expansion waves as well as the fundamentals of subsonic, transonic, supersonic, and hypersonic flow regimes. It further presents the governing equations and their simplified forms along with the associated flow and thermodynamic assumptions. The limits of applicability of the various forms of the governing equations are also discussed. Finally, the chapter briefly presents the equation of state for compressible flows in the form used in aeronautical applications.