The Langley Memorial Aeronautical Laboratory was the first facility built by the National Advisory Committee for Aeronautics (NACA). Langley would be the only NACA test facility until the 1940s and it was home to some of the most advanced research equipment and scientists/engineers during the golden age of aviation development.
However, this reputation for excellence had very humble origins, beginning with the dedication of the first federally funded wind tunnel on June 11, 1920. In a wind tunnel, a stationary object is placed in a tube-like structure and wind is created with a fan, providing researchers an opportunity to observe airflow around the object and the aerodynamic forces that act upon it. Wind tunnels are essential to the creation and testing of aircraft, allowing for experiments on designs without posing major risks to the pilots or to the aircraft.
Wind tunnels have been in international use since the 1800s; only a handful wind tunnels existed in the United States before 1920, including the Wright brothers’ tunnel in Dayton, Ohio. On June 11, 1920, the NACA dedicated its first wind tunnel, the five-foot Atmospheric Wind Tunnel #1 (AWT), in conjunction with the dedication of Langley. Some research had already begun before the dedication, but with the creation of the AWT, the Langley lab was able to begin routine operations and focus its efforts on the field of aeronautics.
When Langley was founded, the United States was far behind Europe in aeronautical technology, and the AWT was constructed as an attempt for American scientists to catch up with their European counterparts. Taking a measured first step, the NACA’s first tunnel, the AWT, was built as a replica of an existing ten-year-old British wind tunnel. This dated design was not going to produce cutting edge research results.
However, even though the AWT was outdated and did not produce important technological advances, it was nonetheless invaluable in educating Langley researchers about aerodynamic testing methods and analysis techniques. With this experience, Langley researchers were able to create the first pressurized wind tunnel, the Variable Density Tunnel (VDT), in 1923, which which was a radical leap forward in wind tunnel design. The VDT dramatically advanced the study of aerodynamics both in the United States and the world.
Today, the wind tunnels at NASA, including those at Ames and Glenn, vary in size and purpose, and are used to test both air- and spacecraft. The various tunnels simulate the various speeds, airflow and temperatures that distinct aircraft might encounter. Simulated flight speeds can range from below the speed of sound to speeds greater than Mach 5.
Though many NASA centers have turned to the digital world to simulate flight conditions, at one point Langley had 23 major wind tunnels, including the National Transonic Facility (NTF), the world’s largest pressurized cryogenic wind tunnel. In the ninety-five years that have passed since the inception of the Langley Memorial Aeronautical Laboratory, the world has witnessed many great achievements in the field of aeronautics, and the first Atmospheric Wind Tunnel served as the starting point for the American contribution to that progress.