Assessment of Technologies for the Silent Aircraft Initiative

Abstract

TheSilentAircraft Initiative produced an aircraft design that combinedmanynewandnovel technologies to give a solution that was predicted to be fuel-efficient as well as extremely quiet. The study presented in this paper seeks to assess the benefits and penalties of each of the proposed technologies. Amethod has been developed that estimates the overall change in fuel consumption and engine noise caused bymodifications to an aircraft design. Themethod sizes a propulsion system for a specified design and determines adjustments to the cruise performance based on changes in the engine components, the installation system, and system weight. The offdesign performance is also calculated so that the noise can be estimated. The method has been applied to show what contribution each silent aircraft technologymade to the overall goal of the project. It also shows the tradeoffs between noise and fuel consumption for various technologies and indicates that there are configurations that can achieve both lower fuel burn and lower engine noise. The method has been used to identify a low-risk configuration of the silent aircraft, for which a new design is presented. Nomenclature A = area, m2 D = drag, kN d = diameter, m