Mechanisms of Jet Noise Reduction and Their Impact on Large-Eddy Simulations (invited)

2011 ◽  
Author(s):  
Daniel Bodony ◽  
Jeonglae Kim ◽  
Jonathan Freund
Keyword(s):  
Noise Reduction ◽  
Jet Noise ◽  
Large Eddy Simulations ◽  
Large Eddy

scholarly journals Nozzles, turbulence, and jet noise prediction

2018 ◽  
Vol 860 ◽  
pp. 1-4 ◽  
Author(s):  
Jonathan B. Freund
Keyword(s):  
Prediction Accuracy ◽  
Jet Noise ◽  
Sound Field ◽  
Field Measurements ◽  
Detailed Comparison ◽  
Large Eddy Simulations ◽  
Noise Prediction ◽  
Large Eddy ◽  
Modelling Procedure ◽  
Flow Turbulence

Jet noise prediction is notoriously challenging because only subtle features of the flow turbulence radiate sound. The article by Brès et al. (J. Fluid Mech., vol. 851, 2018, pp. 83–124) shows that a well-constructed modelling procedure for the nozzle turbulence can provide unprecedented sub-dB prediction accuracy with modest-scale large-eddy simulations, as confirmed by detailed comparison with turbulence and sound-field measurements. This both illuminates the essential mechanisms of the flow and facilitates prediction for engineering design.

Isothermal and heated subsonic jet noise using large eddy simulations on unstructured grids

2018 ◽  
Vol 171 ◽  
pp. 166-192 ◽  
Author(s):  
M. Zhu ◽  
C. Pérez Arroyo ◽  
A. Fosso Pouangué ◽  
M. Sanjosé ◽  
S. Moreau
Keyword(s):  
Unstructured Grids ◽  
Jet Noise ◽  
Large Eddy Simulations ◽  
Large Eddy ◽  
Subsonic Jet

Large-Eddy-Simulations of over-expanded supersonic jet noise for launcher applications

2011 ◽  
Vol 130 (4) ◽  
pp. 2511-2511 ◽  
Author(s):  
Jean-Baptiste Dargaud ◽  
Julien Troyes ◽  
François Vuillot
Keyword(s):  
Supersonic Jet ◽  
Jet Noise ◽  
Large Eddy Simulations ◽  
Supersonic Jet Noise ◽  
Large Eddy

Analysis of Jet-Noise-Reduction Concepts by Large-Eddy Simulation

2007 ◽  
Vol 6 (3) ◽  
pp. 243-285 ◽  
Author(s):  
Michael L. Shur ◽  
Philippe R. Spalart ◽  
Michael Kh. Strelets ◽  
Andrey V. Garbaruk
Keyword(s):  
Noise Reduction ◽  
Low Cost ◽  
Jet Noise ◽  
Physical Models ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Chevron Nozzles ◽  
Automatic Activation ◽  
Computational Resources ◽  
Flux Limiters

The paper outlines the latest improvements to a CFD/CAA numerical system developed by the authors starting in 2001, and presents its application to the evaluation of three noise-reduction concepts. The improvements include a two-step RANS-LES approach to represent complex nozzles much more faithfully, and an accurate algorithm for shock capturing in LES, now based on local automatic activation of flux-limiters. The noise-reduction concepts considered are: beveled nozzles, dual nozzles with fan-flow deflection, and chevron nozzles. The simulations are carried out on PC clusters with at most six processors and on rather modest grids (2–4 million nodes). Nonetheless, in most cases the system is close to the 2–3 dB target accuracy both in terms of directivity and spectrum, while limited in terms of frequency (to a diameter Strouhal number that ranges from 2 to 4, depending on the grid used and the flow regime). Although this limitation is significant, especially for chevron nozzles, the overall message of the paper is that the available CFD/CAA numerical and physical models, properly combined, are capable of predicting the noise of rather complex jets with affordable computational resources, and already today can be helpful in the rapid low-cost analysis of noise-reduction concepts.

Large-Eddy Simulations Analysis of Supersonic Heated Jets with Fluid Injection for Noise Reduction

AIAA Journal ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 3442-3455 ◽  
Author(s):  
Marco Coderoni ◽  
Anastasios S. Lyrintzis ◽  
Gregory A. Blaisdell
Keyword(s):  
Noise Reduction ◽  
Large Eddy Simulations ◽  
Fluid Injection ◽  
Large Eddy ◽  
Heated Jets

Noise reduction analysis of supersonic unheated jets with fluidic injection using large eddy simulations

2018 ◽  
Vol 17 (4-5) ◽  
pp. 467-501 ◽  
Author(s):  
Marco Coderoni ◽  
Anastasios S Lyrintzis ◽  
Gregory A Blaisdell
Keyword(s):  
Noise Reduction ◽  
Sound Pressure ◽  
Sound Propagation ◽  
Large Eddy Simulations ◽  
State University ◽  
Pennsylvania State University ◽  
Baseline Case ◽  
Large Eddy ◽  
Flight Regimes ◽  
Positive Effect

A set of large eddy simulations is used to perform a numerical analysis of fluidic injection as a tool for noise reduction. This technique, developed at the Pennsylvania State University, allows one to turn on and off the air injectors in order to reduce the noise during takeoff and landing without penalizing performance in other flight regimes. Numerical simulations are performed on a military-style nozzle based on the GE F400-series engines, with a design Mach number of 1.65, for overexpanded jet conditions. The numerical results are compared and validated with the outcome of experiments performed at the Pennsylvania State University. For the case chosen, the fluidic injection shows the potential of breaking down shock cells into smaller structures with different orientation and strength. This directly reduces the intensity of broadband shock associated noise, with a positive effect of reducing the overall sound pressure level by more than [Formula: see text] along the direction of maximum sound propagation of the baseline case. The maximum noise reduction was found to be almost [Formula: see text] at 55° on the azimuthal plane in between two lines of injectors.

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