Noise-Source Separation Using Internal and Far-Field Sensors for a Full-Scale Turbofan Engine

Hultgren, Lennart S.; Miles, J. H.

doi:10.2514/6.2009-3220

Cited by 20 publications

(16 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is concluded here that this indicates that the non-plane-wave modes are cut-off in the turbine/duct downstream of the combustor for this particular engine. This is in agreement with the results of Hultgren and Miles 23 in which coherent combustor noise was only detected for frequencies less than about 400+ Hz.…”

Section: Combustor Modal Analysissupporting

confidence: 82%

“…The black squares correspond to the total noise signature from the EVNERT experiment, which is reasonably well predicted by the original ANOPP results (see Ref. 23 for details). The dashed curves represent the post-corrected 46 ANOPP 1/3-octave SPL predictions for the total (black) and combustion (red) noise using the simplified Pratt & Whitney acoustic turbine-transmission formula (6) rather than the ANOPP-GE one (3b).…”

Section: Nasa/tm-2012-217671mentioning

confidence: 48%

“…NASA/TM-2012-217671 Figure 3 shows the original 23 far-field results in the 130 o direction as well as the effects 46 on the ANOPP predictions by replacing the ANOPP-GE turbine-attenuation factor by the simplified Pratt & Whitney formula. The 1/3-octave sound-pressure-level (SPL) results are shown at the four engine power settings of 48, 60, 71, and 87 percent corrected fan speed (flight-idle, approach, cutback, and takeoff conditions) for the 1/3-octave center frequency range of 20 to 1000 Hz.…”

Section: Nasa/tm-2012-217671mentioning

confidence: 99%

“…Hultgren 46,b found that the gain factor obtained from the simplified Pratt & Whitney formula (6) agreed better with the experimental results for frequencies of practical importance. Hultgren 46 reexamined the far-field 1/3-octave SPL results in the 130 o direction by Hultgren and Miles,23 for the same EVNERT dataset as above, by applying a post-correction to the original ANOPP predictions for both the total noise signature and the combustion-noise component. It was found that replacing the ANOPP-GE combustornoise turbine-attenuation function (3b) with the simplified Pratt & Whitney one (6) clearly improved the total-noise predictions and also improved the combustion-noise predictions.…”

Section: Nasa/tm-2012-217671mentioning

confidence: 99%

“…Since flight effects reduce jet noise more than combustor noise, combustor noise can be a significant contributor to aircraft in-flight noise but may be masked by jet noise under the corresponding static-engine test conditions. To overcome this obstacle, researchers [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] developed coherence techniques utilizing engine-internal, as well as far-field, measurements to identify the far-field combustor-noise component. Modal analyses [24][25][26][27][28][29] were also carried out to determine the source and propagation characteristics of combustor noise.…”

Section: Nasa Sti Program In Profi Lementioning

confidence: 99%

See 4 more Smart Citations

A Comparison of Combustor-Noise Models

Hultgren

2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

Self Cite

View full text Add to dashboard Cite

Section: Combustor Modal Analysissupporting

confidence: 82%

Section: Nasa/tm-2012-217671mentioning

confidence: 48%

Section: Nasa/tm-2012-217671mentioning

confidence: 99%

Section: Nasa/tm-2012-217671mentioning

confidence: 99%

Section: Nasa Sti Program In Profi Lementioning

confidence: 99%

See 3 more Smart Citations

A Comparison of Combustor-Noise Models

Hultgren

2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

Self Cite

View full text Add to dashboard Cite

Combustion noise: modeling and prediction

et al. 2019

View full text Add to dashboard Cite

This paper reviews both direct and indirect combustion noise. For convenience, they will simply be referred to as combustion noise and entropy noise. Combustion noise has been studied for well over half a century. However, because of the large number of parameters involved and the complexities inherent in the combustion processes, a widely accepted theory has yet to be developed. For this reason, this review focuses primarily on experimental measurements, semi-empirical relations and empirical but practical prediction methodologies. Important characteristic features and empirical correlations of combustion noise based on open flames and engine noise data are highlighted. Plausible generation of entropy noise by the passage of entropy waves through a nonuniform mean flow was first predicted theoretically circa 1970s. But it took forty years for its existence to be confirmed experimentally. Since then, there have been numerous publications on this subject. They are the primary materials of this review. The fundamental experiment and noise generation mechanism will be discussed first. Of great practical importance is whether there is significant generation of entropy waves inside an engine. This issue and new methods for modeling and predicting internally generated engine entropy noise are items that are examined at some length. Recent advances in computational methods especially in large eddy simulation lead us to envision an important role to be played by high-fidelity numerical simulation in future combustion and entropy noise research and prediction. A critical evaluation of a strategy for investigating and predicting the generation and propagation of these noise components from the combustor of an engine to its exhaust is included in this review.

show abstract

Indirect combustion noise of auxiliary power units

Tam

Parrish

et al. 2013

Journal of Sound and Vibration

View full text Add to dashboard Cite

Noise-Source Separation Using Internal and Far-Field Sensors for a Full-Scale Turbofan Engine

Cited by 20 publications

References 23 publications

A Comparison of Combustor-Noise Models

A Comparison of Combustor-Noise Models

Combustion noise: modeling and prediction

Indirect combustion noise of auxiliary power units

Contact Info

Product

Resources

About