ABSTRACT
For a transonic flight, the free-stream Mach number of an aircraft reaches or exceeds its critical Mach number when local airflow becomes sonic, or supersonic, normally at the most cambered location over its aerofoil. To understand the features of airflow around transonic aircraft, this chapter analyzes the development of shockwave over aerofoil; the effects of shockwave on lift, drag, and stall; and the effects on flight control. Each aircraft should have its designed or nominated critical Mach number, Mcrit, specified by its manufacturer. An aircraft can undertake different maneuvers apart from level flight at an airspeed close to Mcrit, when increase of AoA of an aerofoil is required. The turbulent wake detaches from the surface of an aerofoil behind the shockwave, when the free-stream Mach number Mfs increases. This separation affects the aerodynamics forces just like in subsonic boundary layer separation.
