Airflow over NASA’s X-59, Quiet SuperSonic Technology (QueSST)

The X-59 QueSST is an experimental aircraft that will reach supersonic speeds without producing a loud sonic boom. Those on the ground will hear something like distant thunder as the X-59 passes overhead, around 75 dB. This paper studies the pressure distribution over the nose of the X-59 and the Sound Pressure Level (SPL) on the surface of the X-59 nose (1/3 of the total vehicle length) to better understand how sound propagates through the atmosphere. The resulting SPL over the aircraft nose is 180 – 190 dB, and further the SPL on the ground is calculated to be 43-53 dB. Results show the pressure gradient follows the general shape of the acoustic N-wave produced by supersonic aircraft. They also showcase an increase in pressure and therefore SPL across the vehicle length, like the Bernoulli Equation, even when assumptions made in this study do not fully align with this simplification of the Navier Stokes Equations.