Stunning images captured by physicists at NASA experimenting with a new photographic technology have revealed how supersonic aircraft’s shockwaves move and interact.
The photographs could help the agency develop jets which break the sound barrier without producing a sonic boom, but instead a much quieter rumble.
When NASA scientist JT Heineck got his first glimpse of the images after more than a decade of work on the project, he said: We never dreamt that it would be this clear, this beautiful.
The advanced air-to-air technology was tested in flight, and captured the first ever images of shockwaves from two interacting supersonic aircraft.
I am ecstatic about how these images turned out, said Mr Heineck.
With this upgraded system, we have, by an order of magnitude, improved both the speed and quality of our imagery from previous research.
The pictures capture image of shockwaves – rapid changes in pressure which are produced when an aircraft flies faster than the speed of sounds.
The shockwaves merge as they travel through the atmosphere, and create a sound which is heard on the ground as a sonic boom.
The planes featured in the photographs are T-38s, which were flying only 30 feet apart from each other, while being photographed by a trailing plane only ten feet below them.
We’re looking at a supersonic flow, which is why we’re getting these shockwaves, said Neal Smith, a NASA research engineer.
What’s interesting is, if you look at the rear T-38, you see these shocks kind of interact in a curve, he added.
This is because the trailing T-38 is flying in the wake of the leading aircraft, so the shocks are going to be shaped differently. This data is really going to help us advance our understanding of how these shocks interact.
The photography technique, known as Schlieren photography, relies on variations in the refraction of light caused by the pressure changes in the atmosphere.
Upgrades to NASA’s Schlieren technology meant that the new photographs provide three times the amount of data in the same amount of time.
We’re seeing a level of physical detail here that I don’t think anybody has ever seen before, said Dan Banks, senior research engineer at NASA.
Just looking at the data for the first time, I think things worked out better than we’d imagined. This is a very big step.
The images were originally monochromatic – just shown in shades of grey – but have been colourised by NASA to highlight the pressure changes.
They will be studied to contribute to the development of the X-59 Quiet SuperSonic Technology X-plane, which will soon test its quiet supersonic technologies by flying over residential communities in the US.
The X-59 is designed so that when flying supersonic, people on the ground will hear nothing more than a quiet sonic thump – if anything at all – according to NASA.
Using data gathered in the new photographs, scientists will present details on the noise of these jets to regulators in the US and internationally to help develop rules regarding noise levels for supersonic flights over land.
(c) Sky News 2019: Stunning NASA pictures reveal how supersonic jets create shockwaves