Interior noise in the untreated Gulfstream II Propfan Test Assessment (PTA) aircraftInterior noise on the Gulfstream II Propfan Test Assessment (PTA) aircraft was measured using 19 wing, 22 fuselage, and 32 cabin-interior microphones to determine the sources of the cabin noise. Results from ground and flight test acoustic and vibration measurements and analyses show that the major source of cabin noise was the airborne propfan blade passage frequency tones. The radiated sound pressure levels and the richness of the harmonic content of the propfan increased with increasing altitude. The acoustic output of the propfan also depended on the shaft power, helical Mach number, and blade passage frequency.
Document ID
19890046383
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kuntz, H. L. (Lockheed Aeronautical Systems Co. Burbank, CA, United States)
Prydz, R. A. (Lockheed Aeronautical Systems Co., Kelly Johnson Research and Development Center Burbank, CA, United States)