Hypersonic aerodynamics

Hypersonic aerodynamics are characterized by viscous interaction phenomena, that is, the viscosity of the flow significantly affects the external flow, including shock waves. The curved shock waves chemically alter the surrounding air or gas, creating a partially ionized plasma with their high temperatures (caused in part by significant aerodynamic heating of the body). "Hypersonic" is typically considered to refer to the Mach 5 and faster region of aircraft speed; however, some hypersonic phenomena can exist at speeds as low as Mach 3 (depending on the aircraft and the environment).