Testing on the ground before you take to the sky
About wind tunnel testing
[image-62]Since the time of the Wright brothers, researchers have used wind tunnels to design better aircraft. Wind tunnels are used to model an object in flight by moving air past a stationary object, making it seem like the object is flying. Wind tunnels help NASA test ideas for how to make aircraft better and safer. Engineers can design a new aircraft and before it ever leaves the ground, test it in a wind tunnel to make sure it will fly as it should.
Today’s engineers use sophisticated computer modeling alongside wind tunnel testing to validate aircraft designs. Computers allow full-scale modeling and evaluation across a broad range of test conditions, whereas wind tunnels provide detailed, but more accurate testing of a smaller set of conditions.
NASA also uses wind tunnels to test spacecraft and rockets. These vehicles are designed to operate in space, but spacecraft and rockets have to travel through the atmosphere to get to space. Vehicles that return to Earth or land on other planets also travel through an atmosphere and are tested in wind tunnels.
The Unitary Plan Wind Tunnel (UPWT) complex at NASA Ames Research Center includes the 11-by 11-Foot Transonic and the 9-by 7-Foot Supersonic Wind Tunnels, where researchers have tested generations of commercial and military aircraft and NASA space vehicles.
The UPWT has been instrumental in the development of virtually every domestic commercial transport and military fixed-wing airframe since the 1960’s and is one of the busiest wind tunnels in NASA. Researchers use the UPWT extensively for airframe testing and aerodynamic studies and the facility has played a vital role in every manned spaceflight program, including NASA’s Orion space capsule.
Ames is also home to a number of small-scale aerodynamics facilities and the National Full Scale Aerodynamics Complex, the world's largest wind tunnel.
Featured example: Sonic boom mitigation research
How can Ames help us all fly faster tomorrow?
[image-67]A sonic boom is the thunder-like noise a person on the ground hears when an aircraft or other type of aerospace vehicle flies overhead faster than the speed of sound. Nuisance noise generated by a commercial supersonic jet's sonic booms during cruise, and by its powerful engines at takeoff and landing, has kept the speedy aircraft from entering service in the United States – except for Europe's Concorde, which was limited to trans-Atlantic flights only.
Overland supersonic flight could be one of the most significant opportunities for mobility improvement in the next generation of air transportation. NASA is performing research to enable supersonic cruise by eliminating current barriers in efficiency, environmental and performance. NASA Ames has accomplished groundbreaking research through recent wind tunnel tests. We have established new test techniques and instrumentation that have led to major improvements in our ability to measure and analyze the sonic boom signatures of aircraft.
Featured example: Small scale wind tunnel testing
How do you quickly learn a lot about something that's never been tested?
[image-83]The NASA Ames Fluid Mechanics Laboratory houses small scale wind tunnels and a water channel that are used for aerodynamics testing and flow visualization. The low cost of testing and short lead-time for facility availability enable our small facilities to provide crucial information to guide design decisions and fundamental research.
Ames Aero-Physics branch conducted a series of experiments to gather data using multiple measurement techniques to better understand how air flows on and around the surface of an axisymmetric hill named "FAITH" (Fundamental Aeronautics Investigates The Hill). The data sets will be used to develop and validate computational fluid dynamics methods.
Featured example: Mars rover parachute tests
How do you land a spacecraft on Mars?
[image-99]The parachutes that safely delivered the Mars Exploration Rovers Spirit and Opportunity to Mars in 2004 were tested at the National Full Scale Aerodynamics Complex at NASA's Ames Research Center. More recently, the parachute for NASA's Mars Science Laboratory, a much larger rover, was tested here. Low speed inflation of the parachute on Earth simulates conditions of subsonic entry into the less-dense Martian atmosphere. Prior to full-scale MSL parachute testing, a rigid scale model of the parachute was tested in the Unitary Plan Wind Tunnel 9-by 7-Foot Supersonic Wind Tunnel.
NASA's Mars Science Laboratory's parachute measures more than 65 feet in length, and opens to a diameter of nearly 55 feet. It is the largest disk-gap-band parachute ever built and is shown here inflated with only about 12.5 feet of clearance to both the floor and ceiling of the world’s largest wind tunnel at National Full-Scale Aerodynamics Complex.