Multidisciplinary Design and Optimization of the Silent Aircraft

A “silent†aircraft ” is defined to be an aircraft that, in a typical urban area, is inaudi-ble outside of the airport boundary. This paper describes the creation, implementation, and use of an integrated design tool to predict and optimize the performance and costs associated with producing a novel, commercial aircraft design with a step change in noise reduction. The silent aircraft uses a highly integrated configuration where a quiet propul-sion system is embedded in a Blended-Wing-Body type airframe. This allows the shielding of forward radiated engine noise and the extensive use of acoustic liners. Multidisciplinary aircraft design models, which use a combination of simple physics and empirical relations, are adapted for the silent aircraft configuration. These models are used in conjunction with a multidisciplinary planform optimization capability. The resulting silent aircraft design is assessed in terms of performance and acoustic signature. Significant component noise reductions can be achieved with a design that has a fuel burn competitive with next-generation commercial aircraft. Barriers to achieving the aggressive noise goal of the Silent Aircraft Initiative and the associated required technology developments are described