Generalized Acoustic Analogy Modeling of Hot Jet Noise

AIAA Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Vasily Gryazev ◽  
Annabel P. Markesteijn ◽  
Sergey A. Karabasov
Keyword(s):  
Jet Noise ◽  
Acoustic Analogy

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’.

The influence of jet flow on jet noise. Part 1. The noise of unheated jets

1976 ◽  
Vol 73 (4) ◽  
pp. 753-778 ◽  
Author(s):  
R. Mani
Keyword(s):  
Plug Flow ◽  
Jet Noise ◽  
Sound Field ◽  
Point Of View ◽  
Noise Generation ◽  
Acoustic Analogy ◽  
Mean Flow ◽  
Supersonic Regime ◽  
Noise Data ◽  
Jet Velocity

The present paper and part 2 (adjacent) study the sound field produced by a convected point quadrupole embedded in and moving along the axis of a round plug-flow jet. Only subsonic eddy convection velocities are considered. We examine cold jets here and hot jets in part 2. A principal feature of the study is extensive comparison with jet-noise data. It appears that this simple model problem succeeds in explaining all the major interesting features of jet-noise data, on both hot and cold jets, for jet exit velocities in the low supersonic range. Particular success is achieved in explaining aspects of the data not explainable by the Lighthill acoustic-analogy approach. The picture of jet-noise generation that emerges (at least for jet velocities in the low supersonic regime) is in many respects a striking reaffirmation of the Lighthill point of view. It appears that there is an intrinsic or universal distribution of compact quadrupoles, whose strength and frequency distribution scale with the jet velocity and nozzle diameter as would be expected from simple dimensional reasoning, responsible for jet-noise generation. These quadrupoles are of course convected by the mean flow and satisfactory agreement with the data is obtained by assuming that they are devoid of any intrinsic directionality. There appears to be no significant jet Mach number (compressibility) or jet temperature effect on the scaling of this intrinsic distribution. The essential improvement over the Lighthill analysis is the incorporation of mean-flow shrouding effects on the radiation of the convected quadrupoles. It is perhaps no exaggeration to claim that, with the incorporation of such a shrouding effect, the problem of scaling jet noise with regard to the jet velocity, jet temperature, jet size and the angle from the jet axis appears to be completely resolved. (The ‘scaling’ principle cannot of course be very simply expressed and in fact needs calculations of the sort contained in the present paper to implement it.)

scholarly journals Similarity scaling of jet noise sources for low-order jet noise modelling based on the Goldstein generalised acoustic analogy

2017 ◽  
Vol 16 (6) ◽  
pp. 476-490 ◽  
Author(s):  
Vasily A Semiletov ◽  
Sergey A Karabasov
Keyword(s):  
Jet Noise ◽  
Field Measurements ◽  
Noise Prediction ◽  
Far Field ◽  
Acoustic Analogy ◽  
Noise Sources ◽  
Modelling Framework ◽  
Noise Data ◽  
Field Noise ◽  
Low Order

As a first step towards a robust low-order modelling framework that is free from either calibration parameters based on the far-field noise data or any assumptions about the noise source structure, a new low-order noise prediction scheme is implemented. The scheme is based on the Goldstein generalised acoustic analogy and uses the Large Eddy Simulation database of fluctuating Reynolds stress fields from the CABARET MILES solution of Semiletov et al. corresponding to a static isothermal jet from the SILOET experiment for reconstruction of effective noise sources. The sources are scaled in accordance with the physics-based arguments and the corresponding sound meanflow propagation problem is solved using a frequency domain Green’s function method for each jet case. Results of the far-field noise predictions of the new method are validated for the two NASA SHJAR jet cases, sp07 and sp03 from and compared with the reference predictions, which are obtained by applying the Lighthill acoustic analogy scaling for the SILOET far-field measurements and using an empirical jet-noise prediction code, sJet.

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