NASA Langley Research Center’s Wind Tunnels
These wind tunnels are incredible — just look at the massive scale! The top image (taken in 1950) is of a 19-foot Pressure Wind Tunnel with a 35-feet high by 47-feet wide ellipse. The other photo (taken in 1990 -ed.) is of a 16-foot Transonic Tunnel built in 1939. The caption reads:
Operating transonically or across the speed of sound, the air in the test section travels from about 150 to 1,000 miles per hour. The tunnel is called the “16-Foot” because its test section is approximately 16 feet in diameter. The guide vanes, which form an ellipse 58-feet high and 82-feet wide, cut across each cylindrical tube at a 45 degree angle. Similar sets of vanes at the three other corners of the wind tunnel turn the air uniformly as it rushes through the 1000-foot race-track-like enclosed tube.
Another tidbit about the 16-foot tunnel describes how it was used during World War II to test cooling systems and high-speed propellers as well as some of the first builds of the atomic bomb. NASA Langley actually has dozens of wind tunnels. Today they’re used to test flight dynamics, transonic research, and subtle modifications in aircraft designs via computerized flight simulation.
Read more about NASA Langley’s wind tunnels here.