NASA's new way of measuring sonic booms for X-59 supersonic plane

Currently, commercial aircraft aren't allowed to fly faster than the speed of sound over land because of the objectionable sonic booms they cause for those on the ground. This experimental plane will fly at a cruise speed roughly double that of a commercial jet while keeping aircraft noise down to a quiet ‘sonic thump’ – or even no sound at all – as heard on the ground when the plane flies overhead at supersonic speeds.

To be sure the X-59’s design will perform within expected noise limits, NASA is working closely with its contractor, Lockheed Martin, to create a database of computational fluid dynamics simulations to verify the aircraft’s supersonic performance.

The database will include simulations for all possible combinations of the settings that a pilot uses to control the aircraft and the flight conditions that may be encountered during flight.

In 2019, NASA successfully tested an advanced air-to-air photographic technology in flight, capturing the first-ever images of the interaction of shockwaves from two supersonic aircraft in flight (pictured at the top of this article.) The image features two T-38 Talons, a two-seat twin engine supersonic trainer aircraft.

When aircraft fly faster than the speed of sound, shockwaves travel away from them and are heard on the ground as a sonic boom. With exceptional clarity, NASA captured the flow of these shock waves from supersonic aircraft in 2019, and for the first time, the interaction of the shocks in flight.

The images were captured during the fourth phase of Air-to-Air Background Oriented Schlieren flights, or AirBOS, which took place at NASA’s Armstrong Flight Research Center in Edwards, California. The flight series saw successful testing of an upgraded imaging system capable of capturing high-quality images of shockwaves, rapid pressure changes which are produced when an aircraft flies faster than the speed of sound, or supersonic. Shockwaves produced by aircraft merge together as they travel through the atmosphere and are responsible for what is heard on the ground as a sonic boom.

The system will be used to capture data crucial to confirming the design of the agency’s X-59. The ability to fly supersonic without a sonic boom may one day result in lifting current restrictions on supersonic flight over land.

“Originally monochromatic and shown in our first two pictures as colorized composites, these images are the product of an updated camera system aboard one of our research planes. Researchers use this imagery to study shockwaves as part of our effort to make sonic booms quieter, which may open the future to possible supersonic flight over land!”

www.nasa.gov