Analysis of Acoustic Modeling and Sound Propagation in Aircraft Noise Prediction
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Published: 2018-05-29
Total Pages: 74
ISBN-13: 9781720382652
DOWNLOAD EBOOKAn analysis has been performed of measured and predicted aircraft noise levels around Denver International Airport. A detailed examination was made of 90 straight-out departures that yielded good measurements on multiple monitors. Predictions were made with INM 5, INM 6 and the simulation model NMSIM. Predictions were consistently lower than measurements, less so for the simulation model than for the integrated models. Lateral directivity ("installation effect") patterns were seen which are consistent with other recent measurements. Atmospheric absorption was determined to be a significant factor in the underprediction. Calculations of atmospheric attenuation were made over a full year of upper air data at seven locations across the United States. It was found that temperature/humidity effects could cause variations of up to +/-4 dB, depending on season, for the sites examined. It was concluded that local temperature and humidity should be accounted for in aircraft noise modeling.Plotkin, Kenneth J. and Shepherd, Kevin P. (Technical Monitor)Langley Research CenterNOISE PREDICTION; AIRCRAFT NOISE; ACOUSTIC PROPAGATION; SOUND PROPAGATION; NOISE INTENSITY; MODELS; TEMPERATURE EFFECTS; DIRECTIVITY