The work consisted of flight testing of the quiet-nacelle configuration developed in phase 2 in fulfillment of the FAA upper noise reduction goals for the 727 airplane, along with parallel flight testing of the 727 production nacelle as a baseline. All testing was performed on a model 727-100 airplane, with results extrapolated to the long-body 200 model. The phase 2 nacelles consist of peripheral acoustic lining in all inlets plus double-ring acoustic treatment in the side-engine inlets; acoustically treated engine fan ducts; and multilobe variable-geometry jet noise suppressors discharging through fixed, acoustically lined ejectors, with provision for automatic closure of the ejector inlets for cruise operation. Acoustic propulsion, and aerodynamic performance analyses were made, along with a study of the physical effects of integrating the phase 2 nacelle on both model 727s. A direct-operating-cost (DOC) analysis was prepared based on realistic retrofit installation cost estimates and airplane performance analyses. In addition, a study was made of engine and airframe options available for recovery of performance penalties incurred by installation of phase 2 nacelles. (Author)
727 Noise Retrofit Feasibility. Volume III. Upper Goal Flight Testing and Program Summary
1973
227 pages
Report
Keine Angabe
Englisch
Air Transportation , Noise Pollution & Control , Aircraft , Jet engine noise , Turbojet engines , Acoustic impedance , Design , Commercial planes , Jet engine nacelles , Sandwich panels , Honeycomb cores , Turbojet exhaust nozzles , Acoustic insulation , Flight testing , Costs , Boeing 727 aircraft , JT-8 engines , JT-8D engines , Noise suppressors , Noise reduction , Acoustic panels , Aircraft modification