This work demonstrates a new process for designing a three-dimensional modification to a morphing supersonic aircraft to reduce the perceived noise of a sonic boom at the ground under adverse conditions. Previous work has demonstrated the optimization of a one-dimensional equivalent area representation for various atmospheric profiles. The main contribution of this work is a procedure to enable the design of the three-dimensional outer mold line (OML) based on an optimized equivalent area distribution. The inverse problem of finding a three-dimensional shape matching a one-dimensional equivalent area is described using a gradient optimizer with CART3D and free-form deformations to modify the aircraft surface. This paper presents six modified OMLs for the NASA Concept 25D designed using this methodology. Each OML is predicted to reduce the perceived level of loudness in decibels (PLdB) by approximately 1.23 PLdB according to inviscid analysis. One of these OMLs is further analyzed using viscous analysis revealing that larger modifications may be necessary to achieve the desired noise reduction. The design process presented in this paper can be used to enable the optimization of morphing aircraft for many different conditions including Mach, angle of attack, atmospheric variations, and more.
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