Aeroacoustics Research in Europe: The Ceas-Asc Report on 2001 Highlights

Fisher, Michael J.; Self, Rod H.

doi:10.1006/jsvi.2002.5199

Cited by 6 publications

(5 citation statements)

References 13 publications

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“…Figure 13 compares instantaneous pressure of three cases at a nondimensional observer distance of 12 . Although case (2) has the best computational efficiency, the computation does not predict the wave diffraction at the lip correctly. The secondary radiation peak and interference dip angle expected for this problem do not appear in the prediction.…”

Section: Artificial Selective Damping and Filtersmentioning

confidence: 92%

“…The testing environment is a 1.7 GHz i5 computer with 4 GBytes memory. To arrive at far-field directivity, the computation requires 219 s with the finest uniform mesh, 42 s for case (2) and 83 s for case (3).…”

Section: Artificial Selective Damping and Filtersmentioning

confidence: 99%

“…With a noise reduction target of 50% by 2020 [1], computational aeroacoustics (CAA) is being discussed with increasing frequency. Various attempts have been made to apply CAA methods to airframe/engine noise study both in the EU countries and in the US [2,3]. Generally, CAA is concerned predominantly with obtaining timeaccurate numerical solutions through the use of long-time accurate time-integration strategies and high-order spatial discretization schemes [4].…”

Section: Introductionmentioning

confidence: 99%

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High-order schemes for predicting computational aeroacoustic propagation with adaptive mesh refinement

Peers

Huang

2013

Acta Mech Sin

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High-order schemes based on block-structured adaptive mesh refinement method are prepared to solve computational aeroacoustic (CAA) problems with an aim at improving computational efficiency. A number of numerical issues associated with high-order schemes on an adaptively refined mesh, such as stability and accuracy are addressed. Several CAA benchmark problems are used to demonstrate the feasibility and efficiency of the approach.

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Section: Artificial Selective Damping and Filtersmentioning

confidence: 92%

Section: Artificial Selective Damping and Filtersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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High-order schemes for predicting computational aeroacoustic propagation with adaptive mesh refinement

Peers

Huang

2013

Acta Mech Sin

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“…1,2 Analytical techniques for predicting sound levels from this interaction have been developed. [3][4][5][6][7] However, these were based on linearized flow equations and simplified geometries.…”

Section: Introductionmentioning

confidence: 99%

Simulating nonlinear stator noise for active control

Dyson¹,

Hixon²,

Nallasamy³

et al. 2004

Noise Control Eng. J.

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The intent of this work is to demonstrate that nonlinear effects on realistic geometries can be a tool for fan noise reduction. Noise produced from a rotating blade row's convected vortical gusts impinging upon a stationary blade row (stator) was simulated using novel high order numerical techniques. Results from this simulation indicate nonlinear resonance in a blade passage may be used to reduce turbofan engine noise by exciting high-frequency destructive modes with a more easily controlled low-frequency on-blade actuator. This technique of noise reduction is particularly attractive in a duct when cut-off modes are chosen as the base actuator frequency. A combination of large amplitude actuator produced cut-off modes with their corresponding nonlinear harmonic destructive interference patterns is a potential new area of active noise control research.

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“…With a reduction target of perceived noise level of 50% by 2020 [2], computational aeroacoustics (CAA) is being used with increasing frequency in studying the physics of aerodynamically generated noise. Various attempts have been made to apply CAA methods to airframe/engine noise study both in the EU countries and in the US [3,4]. The general objectives of CAA focus on the prediction of aerodynamic sound sources and the propagation of the generated sound.…”

mentioning

confidence: 99%

Adaptive Mesh Refinement for Computational Aeroacoustics

Huang

Zhang

2005

11th AIAA/CEAS Aeroacoustics Conference

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This thesis describes a parallel block-structured adaptive mesh refinement (AMR) method that is employed to solve some computational aeroacoustic problems with the aim of improving the computational efficiency. AMR adaptively refines and coarsens a computational mesh along with sound propagation to increase grid resolution only in the area of interest.While sharing many of the same features, there is a marked difference between the current and the established AMR approaches. Rather than low-order schemes generally used in the previous approaches, a high-order spatial difference scheme is employed to improve numerical dispersion and dissipation qualities. To use a highorder scheme with AMR, a number of numerical issues associated with fine-coarse block interfaces on an adaptively refined mesh, such as interpolations, filter and artificial selective damping techniques and accuracy are addressed. In addition, the asymptotic stability and the transient behaviour of a high-order spatial scheme on an adaptively refined mesh are also studied with eigenvalue analysis and pseudospectra analysis respectively. In addition, the fundamental AMR algorithm is simplified in order to make the work of implementation more manageable.Particular emphasis has been placed on solving sound radiation from generic aero-engine bypass geometry with mean flow. The approach of AMR is extended to support a body-fitted multi-block mesh. The radiation from an intake duct is modelled by the linearised Euler equations, while the radiation from an exhaust duct is modelled by the extended acoustic perturbation equations to suppress hydrodynamic instabilities generated in a sheared mean flow. After solving the near-field sound solution, the associated far-field sound directivity is estimated by solving the Ffowcs Williams-Hawkings equation. The overall results demonstrate the accuracy and the efficiency of the presented AMR method, but also reveal some limitations. The possible methods to avoid these limitations are given at the end of this thesis.

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Aeroacoustics Research in Europe: The Ceas-Asc Report on 2001 Highlights

Cited by 6 publications

References 13 publications

High-order schemes for predicting computational aeroacoustic propagation with adaptive mesh refinement

High-order schemes for predicting computational aeroacoustic propagation with adaptive mesh refinement

Simulating nonlinear stator noise for active control

Adaptive Mesh Refinement for Computational Aeroacoustics

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