Shape Optimization Methodology for Reducing the Sonic Boom Initial Pressure Rise

Abstract

A shape optimization methodology for reducing the initial shock pressure rise on the ground of a supersonic aircraft is presented. This methodology combines elements from the linearized aerodynamic theory, such as the Whitham F function, with elements from the nonlinear aerodynamic theory, such as the prediction of lift distribution by an Euler or a Navier-Stokes flow solver. It is applied to the optimization of two different airplane concepts developed by Reno Aeronautical and Lockheed Martin, respectively, for the Defense Advanced Research Projects Agency's Quiet Supersonic Platform program. For Reno Aeronautical's laminar-flow supersonic aircraft, the initial shock pressure rise on the ground is reduced by a factor close to 2, from 1.224 psf (58.605 N/m 2 ) at a freestream Mach number of 1.5 to 0.671 psf (32.127 N/m 2 ), while maintaining constant lift For Lockheed Martin's point of departure aircraft, a tenfold reduction of the initial shock pressure rise on the ground is demonstrated, from 1.623 psf (77.71 N/m 2 ) at a freestream Mach number of 1.5 to 0.152 psf (7.278 N/m 2 ), also while maintaining constant lift.