NASA Technical Reports Server (NTRS) 20140010733: The Prediction of Noise Due to Jet Turbulence Convecting Past Flight Vehicle Trailing Edges

by: NASA Technical Reports Server (NTRS)

Publication date: 2014-06-16

Topics: NASA Technical Reports Server (NTRS), NOISE PREDICTION, TRAILING EDGES, AERODYNAMIC NOISE, JET AIRCRAFT, SOUND WAVES, STATIC PRESSURE, TEMPERATURE RATIO, TURBULENCE, AEROACOUSTICS, MACH NUMBER, MATHEMATICAL MODELS, SPECTRA, Miller, Steven A. E.,

Collection: NASA_NTRS_Archive; additional_collections

Language: English

High intensity acoustic radiation occurs when turbulence convects past airframe trailing edges. A mathematical model is developed to predict this acoustic radiation. The model is dependent on the local flow and turbulent statistics above the trailing edge of the flight vehicle airframe. These quantities are dependent on the jet and flight vehicle Mach numbers and jet temperature. A term in the model approximates the turbulent statistics of single-stream heated jet flows and is developed based upon measurement. The developed model is valid for a wide range of jet Mach numbers, jet temperature ratios, and flight vehicle Mach numbers. The model predicts traditional trailing edge noise if the jet is not interacting with the airframe. Predictions of mean-flow quantities and the cross-spectrum of static pressure near the airframe trailing edge are compared with measurement. Finally, predictions of acoustic intensity are compared with measurement and the model is shown to accurately capture the phenomenon.