The Terminal High Altitude Area Defense (THAAD) missile is designed to intercept and destroy ballistic missiles inside or outside the atmosphere while they are in their final, or terminal, phase of flight. The THAAD model shown here was tested at AEDC’s Hypervelocity Wind Tunnel 9 facility in White Oak, Md., to collect high-accuracy static stability and drag data. Once demonstrated, the same test model and instrumentation were used in a test in the von Karman Facility to confirm complementary test capabilities exist between the two AEDC facilities. (U.S. Air Force photo)
This full-scale Terminal High Altitude Area Defense missile tip and infrared seeker window assembly recently underwent aerothermal testing at Arnold Engineering Development Center’s Hypervelocity Wind Tunnel 9 facility in Silver Spring, Md. (Photo by John Lafferty)
Hypervelocity Wind Tunnel 9, and AEDC site located at White Oak near Silver Spring, Md., provides aerodynamic simulation critical to hypersonic system development and hypersonic vehicle technologies.
The facility supports testing for Air Force, Navy, Army, Missile Defense Agency, and NASA programs, as well as advanced hypersonic technologies such as wave-rider-type vehicles, scramjets and transatmospheric space planes.
Tunnel 9 is the primary high Mach number and high Reynolds number facility for hypersonic ground testing and the validation of computational simulations for the Air Force and Department of Defense. Noteworthy advantages over other facilities include a unique storage heater with pressures up to 1,900 atmospheres and temperatures up to 3,650 degrees Rankine. Axisymmetric contoured nozzles for Mach 7, 8, 10 and 14 operation are also available.
When compared to other hypervelocity facilities, which have run times of a few milliseconds, the long test times (up to 15 seconds) available in Tunnel 9 provide higher productivity by allowing for parametric variation, e.g. an angle-of-attack sweep or flow survey, during a single run. The five foot (1.5 meter) diameter test cell accommodates large-scale test articles.
The combination of operational range, long test times and large test cell results in the highest Reynolds number, largest scale ground-test facility in the world, capable of simultaneously collecting continuous pitch-polar static force and moment, pressure and heat transfer data during each run. Having the capability to test at flight-matched Reynolds numbers provides a significant risk reduction for the design and evaluation of hypersonic systems.
Tunnel 9 provides a useful and cost-effective environment for research and development test and evaluation; and for investigating the complex physics associated with hypersonic science and technology. Past testing includes aerodynamic, aerothermal, seeker window thermal-structural and aero-optic, shroud removal, hypersonic inlet, fundamental flow physics and Computational Fluid Dynamics validation experiments.
The tunnel is available to government agencies and commercial industry for unclassified or classified testing. Test models may be designed and constructed at the facility or provided by the customer following consultation and planning with the engineering staff. Instrumentation, assembly and installation is typically performed by the facility's professional staff.
History The heritage of AEDC's White Oak site began with early supersonic research conducted in Germany where supersonic missiles were under development for use against the Allies in World War II.
After the war, critical facilities and scientists were brought to America to continue this ground breaking research. In July 1945, the custody of one of these German wind tunnels was awarded to the Navy to be installed at the Naval Ordnance Laboratory at White Oak, Md.
Tunnel 9 became operational in 1976 providing aerodynamic simulation in critical altitude regimes associated with strategic offensive missile systems, advanced defensive interceptor systems, and hypersonic vehicle technologies.