ABSTRACT
The change or the disturbance in air property always trails behind the moving air particles when airflow is supersonic. As a result, the characteristics of aerodynamics of the airflow change so much that they become fundamentally different from those of air in subsonic flow. This chapter analyzes the two forms of supersonic waves, the oblique shock wave and the expansion wave, from the formation of those waves to the effects of the waves and their aerodynamic features. The airflow passes through a normal shockwave is an irreversible adiabatic process. In this process, the compressible supersonic flow passes through a normal shockwave, and it becomes subsonic. An oblique shockwave is a compression supersonic wave, so the air pressure increases when it passes through an oblique shockwave. A compressible airflow expands when it encounters a pressure decreasing disturbance. A pressure expansion wave can be formed.
