Research instrumentation requirements for flight/wind-tunnel tests of the YF-12 propulsion system and related flight experience

Description of the requirements for a comprehensive flight and wind-tunnel propulsion research program to examine the predictability of inlet performance, evaluate the effects of high-frequency pressure phenomena on inlets, and investigate improved control concepts in order to cope with airframe interactions. This program is unique in that it requires precise similarity of the geometry of the flight vehicle and tunnel modes; the test conditions, including local flow at the inlet; and instrumentation. Although few wind-tunnel instrumentation problems exist, many problems emerge during flight tests because of the thermal environment. Mach 3 flight temperatures create unique problems with transducers, connectors, and wires. All must be capable of withstanding continuous 1000 F temperatures, as well as the mechanical stresses imposed by vibration and thermal cycling.