F-15B tracks sonic waves from X-59 with cutting-edge probes

Wednesday 11th December 2024 01:28 AM

NASA will soon test progress on a key tool for measuring the unique “sonic noises” its quiet X-59 supersonic research plane will produce in flight.

A Shock Probe is a cone-shaped aerial data probe developed with specific characteristics to capture the unique shock waves that the X-59 will produce. Researchers at NASA's Armstrong Flight Research Center in Edwards, California, developed two versions of the probe to collect precise pressure data during supersonic flight. One of the probes is optimized for near-field measurements, capturing shock waves that occur very close to where the X-59 will produce them. The second probe will measure the mean field, collecting data at altitudes between 5,000 and 20,000 feet below the aircraft.

Operation and objectives of the probes

When an aircraft flies supersonic, it generates shock waves that propagate through the surrounding air and produce powerful sonic booms. The X-59 is designed to deflect these shockwaves, reducing the powerful sonic booms to dull thuds. During the test flights, an F-15B aircraft equipped with a shock detection probe attached to its nose will fly with the X-59. The approximately 6-foot probe will continuously collect thousands of pressure samples per second, recording changes in air pressure as the plane passes through the shock waves.

« A shock detection probe acts as a source of truth, comparing predicted data with actual measurements said Mike Frederick, NASA's principal investigator for the probe.

NASA's F-15B Aeronautics Research Test Bed conducts a shock detection probe calibration flight over Edwards, California, August 6, 2024. The probe will measure shock waves emitted by the X -59 from NASA and will provide data likely to modify the limits of supersonic terrestrial flights, which will no longer be based on speed but on sound. This work is part of NASA's Quest mission, whose flagship aircraft is the X-59. Credit: NASA/Steve Freeman

Innovations techniques

« Probes have five pressure ports, one at the tip and four around the cone “, explains Mr. Frederick. “ These ports measure changes in static pressure as the aircraft passes through the shock waves, which helps us understand the shock characteristics of a particular aircraft. The orifices combine their measurements to calculate local pressure, speed and direction of air flow. »

Researchers will soon evaluate improvements to the near-field shock detection probe through test flights, during which the probe, mounted on an F-15B, will collect data by tracking a second F-15 for supersonic flight. The improvements include placing the probe's pressure transducers – devices that measure air pressure on the cone – just 5 inches from its ports.

« The probe will meet the resolution and precision requirements of the Quesst mission ” said Mr. Frederick. “ This project shows how NASA can take existing technologies and adapt them to meet new challenges. »

Illutration caption: A close-up of NASA's shock sensing probe highlights its pressure ports, designed to measure changes in air pressure during supersonic flight. The probe will be mounted on NASA's F-15B Aeronautical Research Test Stand for calibration flights, to validate its ability to measure shock waves generated by the X 59 as part of NASA's Quest mission. NASA aiming to provide data on quiet supersonic flights. Credit: NASA/Lauren Hughes