Implementation of Lighthill's Acoustic Analogy in a Finite/Infinite Elements Framework

Caro, Stéphane; Ploumhans, Paul; Gallez, Xavier

doi:10.2514/6.2004-2891

Cited by 38 publications

(15 citation statements)

References 6 publications

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“…After finite element integration of the LAA equation [10] [11] and rearrangement, one can obtain a discrete weak solution in the form of finite-element variational, ( )…”

Section: Lighthill's Acoustic Analogy Methodsmentioning

confidence: 99%

Noise Simulation Analysis of a Variable Displacement External Gear Pump and Unloading Groove Optimization

Yongkang¹,

Li²,

Yang³

2018

OALib

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The oil pump is an important part of vehicle engine, whose noise and vibration characteristics affect the engine performance significantly. The noises generated by both the pressure and flow fluctuations are the main contributors to the oil pump noise. In this paper, noise analysis of an external gear pump is carried out by using the computational fluid dynamics (CFD) method and The Lighthill's acoustic analogy (LAA) algorithm. The fluid pressure and velocity distributions of the flowfield are firstly calculated by using a CFD model. The noises generated by flowfield are simulated and their sound pressure spectra are obtained by using an LAA-based finite element model. By analyzing the phenomenon of oil trapping, the optimum design of unloading groove is put forward, and then the simulation analysis is carried out. According to the finite element model, the noise level of gear pump is reduced and the effect of noise reduction is achieved. The technique presented in this paper can be regarded as a useful tool for optimization design of gear pumps in vehicle engineering.

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“…After finite element integration of the LAA equation [10] [11] and rearrangement, one can obtain a discrete weak solution in the form of finite-element variational, ( )…”

Section: Lighthill's Acoustic Analogy Methodsmentioning

confidence: 99%

Noise Simulation Analysis of a Variable Displacement External Gear Pump and Unloading Groove Optimization

Yongkang¹,

Li²,

Yang³

2018

OALib

View full text Add to dashboard Cite

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“…The implementation of Lighthill's acoustic analogy was firstly derived by Oberai et al, 3 refer also to Actran User's Guide 2 and Caro et al 4 for instance. The starting point is Lighthill's equation:…”

Section: Iia Theorymentioning

confidence: 99%

Several Computational Aeroacoustics Solutions for the Ducted Diaphragm at Low Mach Number

Piellard

Bailly

2010

16th AIAA/CEAS Aeroacoustics Conference

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A hybrid method of aeroacoustic noise computation based on Lighthill's Acoustic Analogy is applied to investigate the noise radiated by a low Mach number flow through a ducted diaphragm. The simulation method is a two-step hybrid approach relying on Lighthill's acoustic analogy, assuming the decoupling of noise generation and propagation. The first step consists of an incompressible Large Eddy Simulation of the turbulent flow field, during which aerodynamic quantities are recorded. In the second step, a variational formulation of Lighthill's Acoustic Analogy using a finite element discretization is solved in the Fourier space. The sensitive steps consisting in computing and transferring source term data from the fluid mesh to the acoustic mesh are reviewed. Indeed, as fluid and acoustic meshes have different constraints due to the different wavelengths to be resolved, interpolation is required. The method is applied to a three-dimensional ducted diaphragm with low Mach number flow. Although the configuration is symmetric, this study exhibits a very complex three-dimensional flow behavior. Four different aerodynamic solutions are compared with the Direct Noise Computation performed by Gloerfelt & Lafon. Good agreement is found in terms of mean flow as well as on instantaneous behavior and turbulent intensities. Acoustic computations are performed with different mesh refinement and interpolation methods. Comparison with literature data on similar cases shows the method relevancy.

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“…In this paper we present a novel aeroacoustic approach to predict the noise from blowers. This approach is an extension of the variational formulation of Lighthill's analogy, initially proposed by Oberai et al, 1,2 and also presented in Caro et al 3 Such an approach is especially well adapted to treat interior, or ducted, noise problems. To treat blower problems, the new approach makes use of acoustic sources defined both in a volume and on control surfaces which enclose the rotating parts of the blower.…”

Section: Introductionmentioning

confidence: 99%

A New CAA Formulation Based on Lighthill's Analogy Applied to an Idealized Automotive HVAC Blower Using AcuSolve and ACTRAN/LA

Caro¹,

Ploumhans²,

Gallez³

et al. 2005

11th AIAA/CEAS Aeroacoustics Conference

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In this paper, we investigate the use of the variational formulation of Lighthill's analogy, implemented in a Finite/Infinite Element framework. We present an innovative way to handle porous boundaries (or equivalently, control surfaces upon which aerodynamic sources are defined). We show how Lighthill's analogy can be used to predict broadband blower noise. Infinite elements are used to enforce the Sommerfeld radiation boundary condition.A derivation of the analogy is presented and is compared with the derivation of Curle's analogy (extended to handle porous boundaries). The implementation is described and is validated on a test case. Preliminary results on a real automotive HVAC blower case are presented.

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Implementation of Lighthill's Acoustic Analogy in a Finite/Infinite Elements Framework

Cited by 38 publications

References 6 publications

Noise Simulation Analysis of a Variable Displacement External Gear Pump and Unloading Groove Optimization

Noise Simulation Analysis of a Variable Displacement External Gear Pump and Unloading Groove Optimization

Several Computational Aeroacoustics Solutions for the Ducted Diaphragm at Low Mach Number

A New CAA Formulation Based on Lighthill's Analogy Applied to an Idealized Automotive HVAC Blower Using AcuSolve and ACTRAN/LA

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