An ion thruster or ion drive is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating cations by utilizing electricity. The term refers strictly to gridded electrostatic ion thrusters, and is often incorrectly loosely applied to all electric propulsion systems including electromagnetic plasma thrusters.
Wind tunnels are large tubes with air moving inside. The tunnels are used to copy the actions of an object in flight. Researchers use wind tunnels to learn more about how an aircraft will fly. NASA uses wind tunnels to test scale models of aircraft and spacecraft. Some wind tunnels are big enough to hold full-size versions of vehicles. The wind tunnel moves air around an object, making it seem like the object is really flying.
The Ames Research Center (ARC), also known as NASA Ames, is a major NASA research center at Moffett Federal Airfield in California's Silicon Valley. It was founded in 1939 as the second National Advisory Committee for Aeronautics (NACA) laboratory. That agency was dissolved and its assets and personnel transferred to the newly created National Aeronautics and Space Administration (NASA) on October 1, 1958. NASA Ames is named in honor of Joseph Sweetman Ames, a physicist and one of the founding members of NACA. At last estimate NASA Ames has over US$3 billion in capital equipment, 2,300 research personnel and a US$860 million annual budget.
In aerodynamics, a hypersonic speed is one that greatly exceeds the speed of sound, often stated as starting at speeds of Mach 5 and above.
Compressible flow is the branch of fluid mechanics that deals with flows having significant changes in fluid density. Gases, mostly, display such behaviour. While all flows are compressible, flows are usually treated as being incompressible when the Mach number is less than 0.3. The study of compressible flow is relevant to high-speed aircraft, jet engines, rocket motors, high-speed entry into a planetary atmosphere, gas pipelines, commercial applications such as abrasive blasting, and many other fields.
The shock tube is an instrument used to replicate and direct blast waves at a sensor or a model in order to simulate actual explosions and their effects, usually on a smaller scale. Shock tubes can also be used to study aerodynamic flow under a wide range of temperatures and pressures that are difficult to obtain in other types of testing facilities. Shock tubes are also used to investigate compressible flow phenomena and gas phase combustion reactions. More recently, shock tubes have been used in biomedical research to study how biological specimens are affected by blast waves.
Arnold Engineering Development Complex (AEDC), Arnold Engineering Development Center before July 2012, located at Arnold Air Force Base, Tennessee is a ground-based flight test facility operated by the Air Force Test Center.
Rope trick is the term given by physicist John Malik to the curious lines and spikes which emanate from the fireball of certain nuclear explosions just after detonation.
A hypersonic wind tunnel is designed to generate a hypersonic flow field in the working section, thus simulating the typical flow features of this flow regime - including compression shocks and pronounced boundary layer effects, entropy layer and viscous interaction zones and most importantly high total temperatures of the flow. The speed of these tunnels vary from Mach 5 to 15. The power requirement of a wind tunnel increases with the cross section, the flow density and is directly proportional to the third power of the test velocity. Hence installation of a continuous, closed circuit wind tunnel remains a costly affair. The first continuous Mach 7-10 wind tunnel with 1x1 m test section was planned at Kochel am See, Germany during WW II and finally put into operation as 'Tunnel A' in the late 1950s at AEDC Tullahoma, TN, USA for an installed power of 57 MW. In view of these high facility demands, also intermittently operated experimental facilities like blow-down wind tunnels are designed and installed to simulate the hypersonic flow. A hypersonic wind tunnel comprises in flow direction the main components: heater/cooler arrangements, dryer, convergent/divergent nozzle, test section, second throat and diffuser. A blow-down wind tunnel has a low vacuum reservoir at the back end, while a continuously operated, closed circuit wind tunnel has a high power compressor installation instead. Since the temperature drops with the expanding flow, the air inside the test section has the chance of becoming liquefied. For that reason, preheating is particularly critical.
A supersonic wind tunnel is a wind tunnel that produces supersonic speeds (1.2<M<5) The Mach number and flow are determined by the nozzle geometry. The Reynolds number is varied by changing the density level. Therefore, a high pressure ratio is required. Apart from that, condensation of moisture or even gas liquefaction can occur if the static temperature becomes cold enough. This means that a supersonic wind tunnel usually needs a drying or a pre-heating facility. A supersonic wind tunnel has a large power demand, so most are designed for intermittent instead of continuous operation.
The High Power laser Energy Research facility (HiPER), is a proposed experimental laser-driven inertial confinement fusion (ICF) device undergoing preliminary design for possible construction in the European Union. HiPER is the first experiment designed specifically to study the "fast ignition" approach to generating nuclear fusion, which uses much smaller lasers than conventional designs, yet produces fusion power outputs of about the same magnitude. This offers a total "fusion gain" that is much higher than devices like the National Ignition Facility (NIF), and a reduction in construction costs of about ten times.
The University of Texas at Arlington Aerodynamics Research Center (ARC) is a facility located in the southeast portion of the campus operated under the Department of Mechanical and Aerospace Engineering. It was established in 1986 as part of an expansion of UTA's College of Engineering. The ARC contributes to the vision of UTA and the University of Texas System to transform the university into a full-fledged research institution. It showcases the aerodynamics research activities at UTA and, in its history, has established itself as a unique facility at a university level. The wind tunnels and equipment in the facility were mainly built by scouting for and upgrading decommissioned equipment from the government and industry. Currently, Masters and Ph.D. students perform research in the fields of high-speed gas dynamics, propulsion, and Computational fluid dynamics among other projects related to aerodynamics.
Expansion and shock tunnels are aerodynamic testing facilities with a specific interest in high speeds and high temperature testing. Shock tunnels use steady flow nozzle expansion whereas expansion tunnels use unsteady expansion with higher enthalpy, or thermal energy. In both cases the gases are compressed and heated until the gases are released, expanding rapidly down the expansion chamber. The tunnels reach speeds from Mach 3 to Mach 30 to create testing conditions that simulate hypersonic to re-entry flight. These tunnels are used by military and government agencies to test hypersonic vehicles that undergo a variety of natural phenomenon that occur during hypersonic flight.
An expansion tube is a type of impulse facility that is conceptually similar to a shock tube with a secondary diaphragm, an expansion section, a test section, and a dump tank where the endwall would be located in a shock tube. It is typically used to produce high enthalpy flows for high speed aerodynamic flow and aerodynamic heating and atmospheric reentry testing.
An axial turbine is a turbine in which the flow of the working fluid is parallel to the shaft, as opposed to radial turbines, where the fluid runs around a shaft, as in a watermill. An axial turbine has similar construction as an axial compressor, but it operates in the reverse, converting flow of the fluid into rotating mechanical energy.
AEDC Hypervelocity Wind Tunnel 9 is a hypersonic wind tunnel owned by the United States Air Force and operated by National Aerospace Solutions The facility can generate high Mach numbers and high Reynolds for hypersonic ground testing and the validation of computational simulations for the Air Force and Department of Defense.
The High-Enthalpy Arc-Heated Facilities at Arnold Engineering Development Complex provide aerothermal ground test simulations of hypersonic flight over a wide range of velocities and pressure altitudes in support of materials and structures development. The facility is composed of three Arc Heaters: HEAT-H1, HEAT-H2, and Heat-H3 which can heat air up to 13,000 degrees Rankine through a controlled high voltage direct current electric arc discharge. The test unit is owned by the United States Air Force and operated by National Aerospace Solutions.
The MARHy Hypersonic low density Wind Tunnel, located at the ICARE Laboratory in Orléans, France, is a research facility used extensively for fundamental and applied research of fluid dynamic phenomena in rarefied compressible flows. Its name is an acronym for Mach Adaptable Rarefied Hypersonic and the wind tunnel is recorded under this name under the European portal MERIL.
The PHEDRA High Enthalpy low density Wind Tunnel, located at the ICARE Laboratory in Orléans, France, is a research facility used extensively for fundamental and applied research on non equilibrium plasma flows and planetary atmospheric entries. Its name is an acronym for soufflerie à Plasma Hors Equilibre de Rentreés Atmosphériques. Phedra wind tunnel takes part of the European Landscape Network portal MERIL.
