Experimental Study of the Effects of Installation on Single- and Counter-rotation Propeller NoiseNational Aeronautics and Space Administration, Scientific and Technical Information Branch, 1986 - Propellers, Aerial - 30 pages |
Common terms and phrases
acoustic advance ratio angle of attack axial directions azimuthal blade pitch BPF HARMONICS OASPL counter-rotation CR counter-rotation propellers CR propeller CR tractor data were obtained decibels Effects of Installation experimental study four blades four-bladed propeller four-bladed SR propeller fourth harmonic given in figure harmonic levels helical tip Mach high tip speeds high-tip-speed data increase in noise Langley Research Center low tip speeds low-tip-speed measurement range microphone carriage microphone locations nacelle NASA noise levels noise radiation patterns nonzero pitch number of blades peller plane of rotation propeller and counter-rotation propeller axis PROPELLER BPF HARMONICS propeller disk plane propeller installations propeller operating conditions propeller plane PROPELLER RUN pusher installation pusher propeller pylon pylon-mounted reference row of blades second harmonic shown in figure single-rotation sound pressure level spatial SR-2 propeller sting-mounted tions tip Mach number tip speeds runs tractor configuration tractor installation Turboprop unsteady loading operation wake yawed