scholarly journals A phenomenological approach to jet noise: the two-source model

2019 ◽  
Vol 377 (2159) ◽  
pp. 20190078 ◽  
Author(s):  
Christopher K. W. Tam
Keyword(s):  
Jet Noise ◽  
Phenomenological Approach ◽  
Source Model ◽  
Large Set ◽  
Noise Generation ◽  
Theme Issue ◽  
Generation Mechanisms ◽  
Similarity Jet ◽  
Spectrum Data ◽  
Noise Spectra

This is a review of the two-source model of jet noise. The model was developed phenomenologically a number of years ago. One of the principal results associated with this model was the identification of two similarity jet noise spectra. This was accomplished through extensive comparisons with a large set of NASA spectrum data. It was found that these two noise spectra when combined appropriately would fit measured noise spectra of jets in any direction regardless of jet temperature and Mach number. Other experimental data in support of the two-source model have since been found. They are discussed in this paper. One of the purposes of this paper is to elaborate on the flow physics of turbulence, noise generation mechanisms and directivity that are the underpinnings of the model. More recent works show the similarity spectra are applicable, well beyond their original database, to noise of military jets, rockets and even volcanoes. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.

Investigation of Centrifugal Blower Noise

1999 ◽  
Author(s):  
Christopher L. Banks ◽  
Sean F. Wu
Keyword(s):  
Radiation Pattern ◽  
Free Field ◽  
Sound Radiation ◽  
Noise Generation ◽  
Centrifugal Blower ◽  
Noise Radiation ◽  
Passenger Vehicles ◽  
Generation Mechanisms ◽  
Semi Empirical ◽  
Noise Spectra

Abstract This paper presents the results of an ongoing investigation of noise radiation from centrifugal blowers used in passenger vehicles. The semi-empirical formulation previously derived by the authors (1998) for predicting noise spectra of centrifugal blowers running in a free field is extended to centrifugal blowers installed in a HVAC scroll housing. Because of the presence of the scroll and cutoff, the flow fields are different from those in a free field. Accordingly, the noise generation mechanisms become much more difficult to analyze and model. The previous model assumed a monopole type sound radiation pattern, and predicted the broadband component of the noise spectra well. This model is extended to include the contributions of both monopole and directional dipole sound radiation. It is this complex radiation that is characteristic of a centrifugal blower situated inside a scroll housing with a cutoff. Comparisons of the calculated and measured noise spectra were demonstrated, and good agreements were obtained in all cases.

scholarly journals A Study of the Role of Organized Structures in Jet Noise Generation

2003 ◽  
Author(s):  
Ramons Reba ◽  
Satish Narayanan ◽  
Tim Colonius ◽  
Mary Dunlop
Keyword(s):  
Jet Noise ◽  
Noise Generation

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’.

Vortex pairing as a model for jet noise generation

AIAA Journal ◽  
1996 ◽  
Vol 34 (4) ◽  
pp. 669-675 ◽  
Author(s):  
R. C. K. Leung ◽  
S. K. Tang ◽  
I. C. K. Ho ◽  
N. W. M. Ko
Keyword(s):  
Jet Noise ◽  
Noise Generation ◽  
Vortex Pairing

scholarly journals Jet Noise Generation and Suppression

1959 ◽  
Vol 31 (6) ◽  
pp. 850-850
Author(s):  
Erik Mollö‐Christensen
Keyword(s):  
Jet Noise ◽  
Noise Generation
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