Hyper-X flight engine ground testing for X-43 flight risk reduction

Airframe-integrated scramjet engine testing has been completed at Mach 7 flight conditions in the NASA Langley 8-Foot High Temperature Tunnel as part of the NASA Hyper-X program. This test provided engine performance and operability data, as well as design and database verification, for the Mach 7 flight tests of the Hyper-X research vehicle (X-43), which will provide the first-ever airframe-integrated scramjet data in flight. The Hyper-X Flight Engine, a duplicate Mach 7 X-43 scramjet engine, was mounted on an airframe structure that duplicated the entire three-dimensional propulsion flowpath from the vehicle leading edge to the vehicle trailing edge. This model was also tested to verify and validate the complete flight-like engine system. This paper describes the subsystems that were subjected to flight-like conditions and presents supporting data. The results from this test help to reduce risk for the Mach 7 flights of the X-43. Nomenclature 8-Ft. HTT NASA Langley 8-Foot High Temperature Tunnel AETB Alumina-Enhanced Thermal Barrier AOA, α angle of attack (degrees) BLA Boeing Lightweight Ablator C D drag coefficient C L lift coefficient C M pitching moment coefficient ∆C p,cowl pressure coefficient increment due to cowl opening ∆C p,fuel pressure coefficient increment due to p pressure (psia) Q heat flux (BTU/ft 2 sec) q dynamic pressure SCFM standard cubic feet per minute SiH 4 gaseous silane SiO 2 silicon dioxide T temperature (o R) TPS Thermal Protection System VFS Vehicle Flowpath Simulator (used with the HXFE) VIL Vehicle in the Loop X spindle streamwise location with origin at the rotation point of the horizontal wing X-43 flight vehicle designation for the Hyper-X research vehicles β angle of sideslip (degrees) φ fuel equivalence ratio Subscripts comb facility combustor condition t total condition freestream condition isolator condition downstream of the internal inlet and upstream of the combustor ∞ Introduction NASA's Hyper-X program will advance technologies for vehicles utilizing hypersonic air-breathing propulsion from the laboratory to the flight environment by obtaining data on a hydrogen-fueled, airframe-integrated, dual-mode supersonic combustion ramjet (scramjet) propulsion system in flight. 1 These data will provide the first flight validation of analytical and computational techniques and wind-tunnel test techniques used to design and analyze this class of vehicle. The Hyper-X program is jointly conducted by The flight-test project phase of the program involves the fabrication and flight testing of three unpiloted, autonomous Hyper-X research vehicles, designated X-43. These vehicles are fabricated by a contractor team led by …