Aeroacoustics research in Europe: The CEAS-ASC report on 2008 highlights

Juvé, Daniel

doi:10.1016/j.jsv.2009.07.022

Cited by 13 publications

(3 citation statements)

References 40 publications

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“…The amplitude and directivity of each source should lead to the far-field spectral density given in Eqn. (10). If, for example, each element in the RANS mesh acts as a single source located at the centroid of the element, x s , then…”

Section: Point Source Distributionmentioning

confidence: 99%

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Investigation of a Jet-Noise-Shielding Methodology

O’Reilly

Rice

2015

AIAA Journal

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Ongoing research toward the reduction of environmental noise from aircraft is investigating the possible shielding of engine-noise sources by novel airframe configurations. To assess the noise-reduction benefits attainable from such configurations, it is necessary to develop appropriate acoustic evaluation tools. In this paper, a jet-noise-shielding-prediction methodology is described. The Tam-Auriault ("Jet Mixing Noise from Fine-Scale Turbulence," AIAA Journal, Vol. 37, No. 2, 1999, pp. 145-153) jet-noise model with a Reynolds-averaged Navier-Stokes solution input, together with a Fresnel-Kirchhoff diffraction method (Fundamentals of Physical Acoustics, Wiley-Interscience, New York, 2000, pp. 472-494), is used to make isolated and shielded far-field jet-noise predictions. This methodology is employed as a sensitivity-analysis tool to establish the relative importance of the source location, spatial extent, and directivity in jet-noise-shielding predictions. Predictions have been made for a shielded single-stream Mach 0.9 jet, and compared with experimental data. Good qualitative agreement is observed, and the disagreement in the shielding levels is most likely due to underestimation of the source axial extent by the jet-noise model.

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Section: Point Source Distributionmentioning

confidence: 99%

“…Such configurations are already the subject of investigation in a number of research projects [7][8][9][10][11]. Their acoustic benefit is typically quantified by the far-field shielding factor, which is the decibel difference between the installed and isolated jet sound pressure level (SPL) at a far-field receiver.…”

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confidence: 99%

Investigation of a Jet-Noise-Shielding Methodology

O’Reilly

Rice

2015

AIAA Journal

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“…Relatively recent advances in transient coupled CFD-FEA codes allow these flow-structure interactions to be modelled. A study by Juvé (2009) investigated the effect of ballooning and wind noise, and found indications of strong transient effects.…”

Section: Other Noise Sourcesmentioning

confidence: 99%

The Effects of Unsteady On-Road Flow Conditions on Cabin Noise

Oettle¹,

Sims-Williams²,

Dominy³

et al. 2010

SAE Technical Paper Series

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On-road, a vehicle experiences unsteady flow conditions due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. There is increasing concern about potential differences between steady flow conditions that are typically used for development and the transient conditions that occur on-road. This work considers whether steady techniques are able to predict the unsteady results measured on-road, the impact of this unsteadiness on the noise perceived in the cabin and whether minor changes made to the geometry of the vehicle could affect this. Both external aerodynamic and acoustic measurements were taken using a full-size vehicle combined with measurements of the noise inside the cabin. Data collection took place on-road under a range of wind conditions to accurately measure the response of the vehicle to oncoming flow unsteadiness, with steady-state measurements taking place in full-scale aeroacoustic wind tunnels.Overall it was demonstrated that, using a variety of temporal and spectral approaches, steady techniques were able to predict unsteady on-road results well enough to assess cabin noise by correctly taking into account the varying on-road flow conditions. Aerodynamic admittance values remained less than unity in the sideglass region of the vehicle, with the exception of the the region nearest the A-pillar. The reducing unsteady energy at frequencies greater than 10 Hz, combined with the corresponding roll-off in admittance, implies that unsteady frequencies below 10 Hz affect the vehicle most, where the response remains quasi-steady.Quasi-steady cabin noise simulations allowed a subjective assessment of the predicted unsteady cabin noise, where the impact of cabin noise modulations were quantified and found to be important to perception. Minor geometry changes affected the sensitivity of cabin noise to changes in yaw angle, altering modulation and therefore having an important impact on the unsteady wind noise perceived on-road.iii DeclarationThe work in this thesis is based on research carried out at the School of Engineering and Computing Sciences, Durham University, UK. No part of this thesis has been submitted elsewhere for any other degree or qualification and it all my own work unless referenced to the contrary in the text.

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