Acoustical holography-based sound power decomposition of a highly heated, large eddy-simulated supersonic jet

2021 ◽  
Vol 150 (4) ◽  
pp. A131-A131
Author(s):  
Kent L. Gee ◽  
Kevin M. Leete ◽  
Junhui Liu ◽  
Alan T. Wall
Keyword(s):  
Supersonic Jet ◽  
Sound Power ◽  
Large Eddy ◽  
Acoustical Holography

Large-Eddy Simulations of a Supersonic Jet and Its Near-Field Acoustic Properties

AIAA Journal ◽  
2009 ◽  
Vol 47 (8) ◽  
pp. 1849-1865 ◽  
Author(s):  
Junhui Liu ◽  
K. Kailasanath ◽  
Ravi Ramamurti ◽  
David Munday ◽  
Ephraim Gutmark ◽  
...  
Keyword(s):  
Near Field ◽  
Supersonic Jet ◽  
Large Eddy Simulations ◽  
Acoustic Properties ◽  
Large Eddy

Crackle Noise in Heated Supersonic Jets

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Joseph W. Nichols ◽  
Sanjiva K. Lele ◽  
Frank E. Ham ◽  
Steve Martens ◽  
John T. Spyropoulos
Keyword(s):  
Large Scale ◽  
Supersonic Jet ◽  
Supersonic Jets ◽  
Scale Model ◽  
Positive Pressure ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Total Temperature ◽  
Large Scale Flow ◽  
Large Eddies

Crackle noise from heated supersonic jets is characterized by the presence of strong positive pressure impulses resulting in a strongly skewed far-field pressure signal. These strong positive pressure impulses are associated with N-shaped waveforms involving a shocklike compression and, thus, is very annoying to observers when it occurs. Unlike broadband shock-associated noise which dominates at upstream angles, crackle reaches a maximum at downstream angles associated with the peak jet noise directivity. Recent experiments (Martens et al., 2011, “The Effect of Chevrons on Crackle—Engine and Scale Model Results,” Proceedings of the ASME Turbo Expo, Paper No. GT2011-46417) have shown that the addition of chevrons to the nozzle lip can significantly reduce crackle, especially in full-scale high-power tests. Because of these observations, it was conjectured that crackle is associated with coherent large scale flow structures produced by the baseline nozzle and that the formation of these structures are interrupted by the presence of the chevrons, which leads to noise reduction. In particular, shocklets attached to large eddies are postulated as a possible aerodynamic mechanism for the formation of crackle. In this paper, we test this hypothesis through a high-fidelity large-eddy simulation (LES) of a hot supersonic jet of Mach number 1.56 and a total temperature ratio of 3.65. We use the LES solver CHARLES developed by Cascade Technologies, Inc., to capture the turbulent jet plume on fully-unstructured meshes.

Large Eddy Simulations of Supersonic Jet Flows for Aeroacoustic Applications

2015 ◽  
Author(s):  
Carlos Junqueira-Junior ◽  
Sami Yamouni ◽  
Joao Luiz F. Azevedo ◽  
William Wolf
Keyword(s):  
Supersonic Jet ◽  
Large Eddy Simulations ◽  
Jet Flows ◽  
Large Eddy

Numerical Investigation of 3-D Supersonic Jet Flows Using Large-Eddy Simulation

2012 ◽  
Vol 11 (7-8) ◽  
pp. 783-812 ◽  
Author(s):  
S.-C. Lo ◽  
K. M. Aikens ◽  
G. A. Blaisdell ◽  
A. S. Lyrintzis
Keyword(s):  
Large Eddy Simulation ◽  
Numerical Investigation ◽  
Supersonic Jet ◽  
Jet Flows ◽  
Eddy Simulation ◽  
Large Eddy

Near-field acoustical holography incorporating compressive sampling: Effect of measurement distance and array density

2020 ◽  
Vol 68 (6) ◽  
pp. 470-489
Author(s):  
Tongyang Shi ◽  
Weimin Thor ◽  
J. Stuart Bolton
Keyword(s):  
Sound Source ◽  
Near Field ◽  
Source Region ◽  
Sampling Rate ◽  
Sound Field ◽  
Compressive Sampling ◽  
Sound Power ◽  
L1 Norm ◽  
Measured Intensity ◽  
Acoustical Holography

To identify sound source locations and strength by using near-field acoustical holography (NAH), many microphones are generally required in order to span the source region and to ensure a sufficiently high spatial sampling rate. It is often the case that hundreds of microphones are needed, so such measurements are costly, which has limited the application of NAH in industrial settings. Recently, however, it has been shown that it is possible to accurately identify concentrated sound sources with a limited number of microphones based on compressive sampling theory. Here, the theory of the four NAH methods that were studied in the present work, that is, statistically optimized near-field acoustical holography (SONAH), wideband acoustical holography (WBH), l1-norm minimization, and a hybrid compressive sampling method, is briefly reviewed. Note that the latter three procedures incorporate elements of compressive sampling. Then, a simulation with one monopole as the sound source was conducted to illustrate some basic characteristics of these algorithms. In the experimental portion of the work, a multi-element loudspeaker was used as the sound source. A near-field intensity scan was conducted to measure both the true intensity spatial distribution and the sound power generated by the loudspeaker to provide a basis against which the values obtained from the holography reconstructions could be compared. The sound field was reconstructed by using both near- and far-field measurements, and the number of microphone measurements used to reconstruct the sound field was systematically decreased by increasing the spacing between microphones. Both in the simulation and experiment, the sound field was reconstructed by using the four NAH methods mentioned above. Then, the reconstruction results were comparedwith the measured intensity results in terms of spatial localization and sound power, and the benefits of the compressive sampling approach are illustrated.

Influence of Pavement Roughness on Tire Noise

1999 ◽  
Author(s):  
Richard J. Ruhala ◽  
Courtney B. Burroughs
Keyword(s):  
Power Spectra ◽  
Leading Edge ◽  
Sound Power ◽  
Acoustic Intensity ◽  
Radiated Noise ◽  
Tire Noise ◽  
Pavement Roughness ◽  
Different Types ◽  
Acoustical Holography ◽  
Nearfield Acoustical Holography

Abstract In this study, the influence of the levels of pavement roughness on tire noise is examined using Nearfield Acoustical Holography (NAH) to measure noise from single tires mounted on a two-wheel trailer towed over different types of pavements. Contributions to the radiated noise from the leading edge, trailing edge, and sidewall of two tires are identified. Two experimental tires — a blank tire and a monopitch tire — are evaluated on three pavements — smooth asphalt, stud-damaged concrete, and Ellsworth — at 56 km/hr. From the measured complex pressure, acoustic intensity is reconstructed on side plane of the tires using NAH procedures. Additionally, sound power spectra levels are presented. Tire noise generating mechanisms associated with each pavement are inferred from measurements. The experimental results are compared with theories on pavement-induced tire noise available in the literature.

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