Propeller noise measurements inf DNW on the fuselage of a twin engine aircraft model

Results of sound pressure measurements on the fuselage wall of a twin engine propeller driven model are presented. The tests were carried out in the German-Dutch low speed wind tunnel DNW in the Netherlands. The model was equipped with either metallic propeller blades or composite blades. The propeller diameter was 0.762 m. Six microphones were...

In-flight acoustic measurements in the engine intake of a Fokker F28 aircraft

Acoustic measurements were carried out in the engine intake ducts of a Fokker F28 aircraft during flight. One of the two tail-mounted, low by-pass ratio engines having a hard-walled intake was instrumented to determine the amplitudes of the circumferential modes which constitute the sound field. In the other engine the impedance of the inlet...