NASA to test X-59 shockwave measurement technology

Dec. 16 () –

NASA is set to test advances made in a key tool for measuring the unique ‘sonic booms’ that its silent supersonic aircraft X-59 will occur during flight.

A shock detection probe is a conical-shaped air data probe developed with specific features 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 measurementscapturing the shock waves that occur very close to where the X-59 will generate them. The second impact detection probe It will measure the center of the field and collect data at altitudes between 5,000 and 20,000 feet below the aircraft.

When an aircraft flies at supersonic speeds, it generates shock waves that travel through the surrounding air, producing loud sonic booms. The X-59 is designed to deflect those shock waves, reducing loud sonic booms to quieter sonic booms. During the test flights, an F-15B aircraft with a crash detection probe attached to its nose will fly with the X-59. The approximately 1.80 meter probe will continuously collect thousands of pressure samples per second, capturing air pressure changes as it flies through shock waves. Data from the sensors will be vital to validating computer models that predict the strength of the shock waves produced by the X-59, the centerpiece of NASA’s Quesst mission.

“An impact detection probe acts as a source of truth, comparing predicted data with real-world measurements,” he said. in a statement Mike Frederick, NASA principal investigator for the probe.

For the near-field probe, the F-15B will fly close to the X-59 at its cruising altitude of approximately 18,000 meters, using a “follow the leader” configuration that will allow researchers to analyze shock waves in real time. The medium field probe, intended for separate missions, It will collect more useful data as the shock waves travel closer to the ground.

The probes’ ability to pick up small changes in pressure is especially important for the X-59, since its shock waves are expected to be much weaker than those of most supersonic aircraft. By comparing data from the probes with predictions from advanced computer models, researchers can evaluate more accurately.

“The probes have five pressure ports, one at the tip and four around the cone,” explains Frederick. “These ports measure static pressure changes as the plane flies through the shock waves, which helps us understand the crash characteristics of a particular aircraft.” These ports combine their measurements to calculate local pressure, velocity, and airflow direction.

Researchers will soon evaluate upgrades to the near-field impact detection probe through test flights, in which the probe, mounted on an F-15B, will collect data by chasing a second F-15 during supersonic flight. Updates to the probe include placing the pressure transducers – devices that measure air pressure in the cone – just 12 centimeters from its ports. Previous designs placed these transducers almost 3 meters away, which delayed the recording time and distorted the measurements.

The temperature sensitivity of previous designs also presented a challenge, causing fluctuations in accuracy when conditions changed. To solve this, the team designed a heating system to keep the pressure transducers at a constant temperature during flight.