Modified jet noise source model for twin-jet shielding analysis

1983 ◽  
Author(s):  
C. GERHOLD ◽  
C. KIM
Keyword(s):  
Noise Source ◽  
Jet Noise ◽  
Source Model

scholarly journals Anisotropic source modelling for turbulent jet noise prediction

2019 ◽  
Vol 377 (2159) ◽  
pp. 20190075 ◽  
Author(s):  
Xihai Xu ◽  
Xiaodong Li
Keyword(s):  
Large Scale ◽  
Noise Source ◽  
Jet Noise ◽  
Source Model ◽  
Noise Prediction ◽  
Reynolds Stresses ◽  
Acoustic Analogy ◽  
Mean Flow ◽  
Navier Stokes Equation ◽  
Anisotropic Source

An anisotropic component of the jet noise source model for the Reynolds-averaged Navier–Stokes equation-based jet noise prediction method is proposed. The modelling is based on Goldstein's generalized acoustic analogy, and both the fine-scale and large-scale turbulent noise sources are considered. To model the anisotropic characteristics of jet noise source, the Reynolds stress tensor is used in place of the turbulent kinetic energy. The Launder–Reece–Rodi model (LRR), combined with Menter's ω -equation for the length scale, with modified coefficients developed by the present authors, is used to calculate the mean flow velocities and Reynolds stresses accurately. Comparison between predicted results and acoustic data has been carried out to verify the accuracy of the new anisotropic source model. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.

Wavepacket modeling of the jet noise source

2018 ◽  
Vol 17 (1-2) ◽  
pp. 52-69 ◽  
Author(s):  
Dimitri Papamoschou
Keyword(s):  
Noise Source ◽  
Jet Noise ◽  
Polar Angle ◽  
Sound Intensity ◽  
Source Model ◽  
Physical Models ◽  
Sufficient Information ◽  
Far Field ◽  
Noise Sources ◽  
The Difference

This study is motivated by the need for physical models for the jet noise source to be used in practical noise prediction schemes for propulsion–airframe integration concepts. The basis for the source model is an amplitude-modulated traveling wave—the wavepacket. The source is parameterized and the parameters are determined by minimizing the difference between the modeled and experimental sound intensity distributions in the far field. Even though the pressure signal that reaches the far field is highly filtered, sufficient information is available to construct a wavepacket with reasonable physical characteristics. A simple stochastic extension of this concept shows a connection between the shape of the far-field sound pressure level spectrum and the emission polar angle. It suggests that the broadening of the spectrum with increasing polar angle from the downstream axis can be explained on the basis of a single noise source (the wavepacket), rather than the prevailing model of two distinct noise sources, one coherent and the other incoherent.

Jet noise source measurements using PIV

1999 ◽  
Author(s):  
John Seiner ◽  
Larry Ukeiley ◽  
Michael Ponton
Keyword(s):  
Noise Source ◽  
Jet Noise

SAMURAI - jet noise source analysis of a V2500 engine

2016 ◽  
Author(s):  
Henri A. Siller ◽  
Alessandro Bassetti ◽  
Stefan Funke
Keyword(s):  
Noise Source ◽  
Jet Noise ◽  
Source Analysis

scholarly journals Jet-Surface Interaction Test: Phased Array Noise Source Localization Results

2012 ◽  
Author(s):  
Gary G. Podboy
Keyword(s):  
Source Localization ◽  
Phased Array ◽  
Noise Source ◽  
Jet Noise ◽  
Companion Paper ◽  
Far Field ◽  
Sound Waves ◽  
Axial Distribution ◽  
Noise Sources ◽  
Interaction Test

An experiment was conducted to investigate the effect that a planar surface located near a jet flow has on the noise radiated to the far-field. Two different configurations were tested: 1) a shielding configuration in which the surface was located between the jet and the far-field microphones, and 2) a reflecting configuration in which the surface was mounted on the opposite side of the jet, and thus the jet noise was free to reflect off the surface toward the microphones. Both conventional far-field microphone and phased array noise source localization measurements were obtained. This paper discusses phased array results, while a companion paper discusses far-field results. The phased array data show that the axial distribution of noise sources in a jet can vary greatly depending on the jet operating condition and suggests that it would first be necessary to know or be able to predict this distribution in order to be able to predict the amount of noise reduction to expect from a given shielding configuration. The data obtained on both subsonic and supersonic jets show that the noise sources associated with a given frequency of noise tend to move downstream, and therefore, would become more difficult to shield, as jet Mach number increases. The noise source localization data obtained on cold, shock-containing jets suggests that the constructive interference of sound waves that produces noise at a given frequency within a broadband shock noise hump comes primarily from a small number of shocks, rather than from all the shocks at the same time. The reflecting configuration data illustrates that the law of reflection must be satisfied in order for jet noise to reflect off of a surface to an observer, and depending on the relative locations of the jet, the surface, and the observer, only some of the jet noise sources may satisfy this requirement.

Wavepacket noise source model for microphone array data analysis of hot supersonic jets

2013 ◽  
Vol 134 (5) ◽  
pp. 4127-4127 ◽  
Author(s):  
Philip Morris ◽  
Robert Dougherty ◽  
Chris Nelson ◽  
Alan Cain ◽  
Kenneth Brentner
Keyword(s):  
Data Analysis ◽  
Noise Source ◽  
Microphone Array ◽  
Source Model ◽  
Supersonic Jets ◽  
Array Data
Sign in / Sign up

Export Citation Format

Share Document