Joe Syler, Aerospace Testing Alliance outside machinist, makes an adjustment to the Ares I first stage booster model in the center’s von Karman Facility’s Tunnel B prior to the resumption of heat transfer testing. (Photo by David Housch)
A model of the X-15 rocket shown in AEDC’s von Karman Gas Dynamics Facility wind tunnel A. The X-15 underwent air worthiness and stability testing in the late 1950s. AEDC played a major role in the development of the X-15 and continues to provide instrumental aeronautical tests for U.S. military, NASA, and commercial air and space craft.
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)
The von Karman Gas Dynamics Facility (VKF) is comprised of a supersonic wind tunnel (Tunnel A) and two hypersonic wind tunnels (Tunnels B and C). These tunnels provide high-quality flow in the Mach number 1.5 to 10 flight regime and operate as variable-density, continuous-flow units. Tunnels A, B and C offer large test sections (40 to 50 in.) for aerodynamic testing and have unique operating capabilities.
The tunnels are used extensively to obtain large aerodynamic and aerothermodynamics databases to develop supersonic and hypersonic flight vehicles. Customers use these facilities to conduct testing for static stability, pressure loads, jet interaction, store separation and vehicle staging, heat transfer, inlet integration, material sampling thermal mapping, and dynamic stability, including forced and free oscillation.
The VKF tunnels have several unique features. Tunnel A has a computer-controlled, continuous curvature nozzle that can vary Mach number from 1.5 to 5.5. In addition, Tunnels B (Mach 6 and 8) and C (Mach 4, 8, and 10) are the only operational hypersonic T&E facilities with continuous flow capabilities. The Mach number 4 Tunnel C configuration can match true flight conditions from 56,000 to 105,000 ft. Tunnel C also an aerothermal environment for testing materials proposed for use on space vehicles and aircraft. This one-of-a-kind hypersonic wind tunnel can subject flight hardware to a combination of aerodynamic and thermodynamic effects up to 1440 degrees to study how materials respond to the combined effects of external heating, internal heat conduction, and pressure loading. Each tunnel is also equipped with a unique model injection system to allow reconfiguration of test articles during air-on operation, resulting in high data productivity for obtaining aerodynamic databases. Special photographic techniques are used in the tunnels to visualize shock waves and heating patterns.
Virtually every high-speed flight vehicle has required testing in Tunnels A/B/C, from reentry and tactical vehicles and space capsules, to the X-planes and winged vehicles. Extensive testing in Tunnels A, B and C has been performed on the NASA Space Transport System, Ares, National Aerospace Plan, X-37 orbital test vehicle, X-43 reusable launch vehicle and Atlas space launch vehicle.
The origin of AEDC's VKF may be traced back to the end of World War II, when General of the Air Force H.H. "Hap" Arnold -- then Army Air Forces commander and the man for whom the center was named -- sought to determine how the Germans had made such rapid progress in developing high-performance jet aircraft and rocket-powered missiles. He enlisted the help of Dr. Theodore von Karman, one of history's great aeronautical scientists, to conduct a survey of the German facilities as the war was ending.
Dr. von Karman's subsequent report recommended the Air Force create a center with "...wind tunnel facilities to attain speeds up to three times the velocity of sound, with large enough test sections to accommodate models of reasonable size, including jet propulsion units, and one ultrasonic wind tunnel for exploration of the upper frontier of the supersonic speed range. Ample facilities for the study of combustion and other characteristics of propulsion systems at very high altitudes should be provided..."
The decision to proceed with a gas dynamic facility was made in 1950 at a Washington, D.C., meeting by representatives of the Air Force, Navy, NACA (forerunner of NASA), the government's Research Development Board and the aircraft industry.
The Actual directive to the Corps of Engineers to proceed with construction did not come until almost two years later. In 1959, two years after completion of the two large continuous-flow tunnels, the facility was renamed after Dr. von Karman, then chief scientific advisor to the
Air Force and an enthusiastic participant helping AEDC.