Methodology for Conducting Scaled Sonic-Boom Flight Tests Using Unmanned Aircraft Systems

This paper explores how a scaled aircraft can be used tomodel a full-scale aircraft sonic boom. All scales from 5 to 100% are investigated. To create a scaled pressure profile that represents the full-size aircraft, the Mach number, static margin, angle of attack, and canard incidence angle are set equal to the full-size aircraft’s parameters. By setting these parameters, the scaled unmanned aircraft creates an F-function proportional to the square of the scaling ratio. To scale the acoustic advance, the propagation distance must be reduced. One way to accomplish this scaling is to fly at a lower altitude; however, to generate the proper wing loading, a pull-up maneuver must be performed. Alternatively, the subscale vehicle can be flown at the full-scale aircraft cruise altitude, and data are recorded at an intermediate altitude by a chase aircraft with a pressure probe. Using this method, the test aircraft properly models the shape of the full-scale aircraft sonic boom. The duration and overpressure of its sonic boom are respectively linearly and quadratically proportional to its scale. The lower bound in size is explored by considering manufacturing, data acquisition, and molecular relaxation.