It wasn’t an easy shot to get, but the end results of NASA’s efforts to capture air-to-air images of supersonic shockwaves sure seem worth it.
To take these unprecedented photos, the space agency updated the imaging system on one of its Beechcraft B200 Super King Air aircraft. NASA scientists upgraded the camera so that it could capture a wider field of view, improved its connection to data storage, and increased its frame rate to 1,400 frames per second.
Then, the B200 flew up to about 9,100 meters. Meanwhile, two T-38 jets flew in formation, less than 10 meters apart, only about 600 meters away from the B200 aircraft. All three planes had to be in the right place, and a result, the camera system took exceptionally high-quality images of shockwaves created by the two T-38 aircraft and the interaction of the shockwaves between the two jets.
“We never dreamt that it would be this clear, this beautiful,” J.T. Heineck, of NASA’s Ames Research Center in Mountain View, said. “I am ecstatic about how these images turned out. With this upgraded system, we have, by an order of magnitude, improved both the speed and quality of our imagery from previous research.”
Quieter sonic booms
An aircraft traveling faster than the speed of sound creates a shockwave, essentially a pressure front that pushes into the surrounding air. In this case, flying the B200 aircraft above the T-38s provided a new vantage point for observing shockwaves, as well as their interaction. Ground-based observers perceive a sonic boom as the shockwave from a supersonic aircraft crosses their location.
This photography effort wasn’t a project to create art, even though the resulting images are stunning. Rather, scientists want to better understand the formation of shockwaves and their resulting sonic booms as part of a NASA project to develop quieter supersonic aircraft.
NASA and Lockheed Martin are developing a “low boom” flight demonstrator, the X-59 aircraft, to test technologies for lower-impact sonic booms. This aircraft may be ready for test flights in 2022, and NASA wants to have equipment ready to measure its capabilities. By then, NASA wants to have perfected its use of the schlieren imagery technique that captured these new images and data.
With this kind of data, NASA or commercial companies may be able to convince regulators to permit over-land, less-disruptive supersonic air travel. Although the Concorde was done in by a number of factors and stopped flying in 2003, one of its biggest limitations was the fact that it could only fly from coastal destinations to coastal destinations above the speed of sound.
Listing image by NASA
via Ars Technica https://arstechnica.com
March 6, 2019 at 08:26AM