Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781722960742
Total Pages : 106 pages
Book Rating : 4.9/5 (67 download)
Book Synopsis Broadband Fan Noise Generated by Small Scale Turbulence by : National Aeronautics and Space Administration (NASA)
Download or read book Broadband Fan Noise Generated by Small Scale Turbulence written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the development of prediction methods for broadband fan noise from aircraft engines. First, experimental evidence of the most important source mechanisms is reviewed. It is found that there are a number of competing source mechanism involved and that there is no single dominant source to which noise control procedures can be applied. Theoretical models are then developed for: (1) ducted rotors and stator vanes interacting with duct wall boundary layers, (2) ducted rotor self noise, and (3) stator vanes operating in the wakes of rotors. All the turbulence parameters required for these models are based on measured quantities. Finally the theoretical models are used to predict measured fan noise levels with some success. Glegg, Stewart A. L. Langley Research Center FAN BLADES; NOISE (SOUND); TURBULENCE; WAKES; NOISE REDUCTION; NOISE INTENSITY; AERODYNAMIC NOISE; MATHEMATICAL MODELS; WALLS; VANES; ROTOR AERODYNAMICS; PREDICTION ANALYSIS TECHNIQUES; DUCTS; BOUNDARY LAYERS; AIRCRAFT ENGINES...