Interior Noise Control by Fuselage Design for High-speed Propeller-Driven Aircraft

Abstract

An analytic study was performed to define the acoustical treatment weight penalties that are required to provide an interior noise level of 80 dBA in propfan-powered aircraft at Mach 0.8 cruise. The prediction method, described in a companion paper, combines Koval's theory for cylindrical shell noise transmission loss (TL) with Beranek and Work's method for multilayered acoustic treatment analyses. Three fuselage diameters are studied which represent commuter, narrow-body, and wide-body aircraft. The calculated acoustic treatment weight penalties range from 1.7 to 2.4% of aircraft takeoff gross weight (TOGW) for add-on designs. Advanced noise reduction designs, those which permit structural modifications, reduce the acoustic treatment weight penalties to 1.5% TOGW for aluminum aircraft and from 0.74 to 1.4% TOGW for composite fuselage construction. The wide-body results agree with the weight penalty estimates of an earlier turboprop aircraft study.