Aerothermodynamics and Transition in High-Speed Wind Tunnels at NASA Langley

Immediately after World War n, the National Advisory Committee for Aeronautics (NAGA) recognized the urgency for supplementing subsonic wind tunnels used effectively during wartime with faster-than-sound facili­ ties. Accordingly, a number of supersonic and pilot hypersonic facilities were developed by the NACA in the mid-to-Iate 1940s and 1950s (Baals & Corliss 1981) to study aerodynamic, aerothermodynamic [that is, heating due to the conversion of kinetic energy of the test gas to thermal energy as a result of shock waves or surface friction (Neumann & Hayes 1986)], and fluid-dynamic characteristics of the flow about models, including transition from laminar to turbulent boundary layers. (The term super­ sonic is used herein to define the speed regime between Mach 1.1 to 5, and the term hypersonic corresponds to Mach numbers in excess of 5). Interest in aerothermodynamics increased dramatically in the 1950s primarily