A Computational Aeroacoustic Method for Near and Far-field Vehicle Noise Predictions

A Computational Aeroacoustic Method for Near and Far-field Vehicle Noise Predictions PDF Author: N. Sarigul-Klijn
Publisher:
ISBN:
Category :
Languages : en
Pages :

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A Computational Aeroacoustic Method for Near and Far-field Vehicle Noise Predictions

A Computational Aeroacoustic Method for Near and Far-field Vehicle Noise Predictions PDF Author: N. Sarigul-Klijn
Publisher:
ISBN:
Category :
Languages : en
Pages :

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A Method to Predict Automobile Aeroacoustic Near and Far Field Noise

A Method to Predict Automobile Aeroacoustic Near and Far Field Noise PDF Author: Douglas William Dietz
Publisher:
ISBN:
Category :
Languages : en
Pages : 170

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Identification of Near Sound Field Boundary and Far Field Noise Predictions

Identification of Near Sound Field Boundary and Far Field Noise Predictions PDF Author: Kyong Sang Lee
Publisher:
ISBN:
Category :
Languages : en
Pages : 272

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Computational Aeroacoustics

Computational Aeroacoustics PDF Author: Jay C. Hardin
Publisher: Springer Science & Business Media
ISBN: 1461383420
Category : Science
Languages : en
Pages : 525

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Book Description
Computational aeroacoustics is rapidly emerging as an essential element in the study of aerodynamic sound. As with all emerging technologies, it is paramount that we assess the various opportuni ties and establish achievable goals for this new technology. Essential to this process is the identification and prioritization of fundamental aeroacoustics problems which are amenable to direct numerical siIn ulation. Questions, ranging from the role numerical methods play in the classical theoretical approaches to aeroacoustics, to the correct specification of well-posed numerical problems, need to be answered. These issues provided the impetus for the Workshop on Computa tional Aeroacoustics sponsored by ICASE and the Acoustics Division of NASA LaRC on April 6-9, 1992. The participants of the Work shop were leading aeroacousticians, computational fluid dynamicists and applied mathematicians. The Workshop started with the open ing remarks by M. Y. Hussaini and the welcome address by Kristin Hessenius who introduced the keynote speaker, Sir James Lighthill. The keynote address set the stage for the Workshop. It was both an authoritative and up-to-date discussion of the state-of-the-art in aeroacoustics. The presentations at the Workshop were divided into five sessions - i) Classical Theoretical Approaches (William Zorumski, Chairman), ii) Mathematical Aspects of Acoustics (Rodolfo Rosales, Chairman), iii) Validation Methodology (Allan Pierce, Chairman), iv) Direct Numerical Simulation (Michael Myers, Chairman), and v) Unsteady Compressible Flow Computa tional Methods (Douglas Dwoyer, Chairman).

Computational Aeroacoustics of Propeller Noise in the Near and Far Field

Computational Aeroacoustics of Propeller Noise in the Near and Far Field PDF Author: D.W. Forsyth
Publisher:
ISBN:
Category :
Languages : en
Pages : 59

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39th AIAA Aerospace Sciences Meeting and Exhibit

39th AIAA Aerospace Sciences Meeting and Exhibit PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 724

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Airfoil Aeroacoustics, LES and Acoustic Analogy Predictions

Airfoil Aeroacoustics, LES and Acoustic Analogy Predictions PDF Author: William Roberto Wolf
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 238

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The development of physics-based noise prediction tools for analysis of aerodynamic noise sources is of paramount importance since noise regulations have become more stringent. Direct simulation of aerodynamic noise remains prohibitively expensive for engineering problems because of the resolution requirements. Therefore, hybrid approaches that consist of predicting nearfield flow quantities by a suitable CFD simulation and farfield sound radiation by aeroacoustic integral methods are more attractive. In this work, we apply the fast multipole method (FMM) to accelerate the solution of boundary integral equation methods such as the boundary element method (BEM) and the Ffowcs Williams & Hawkings (FWH) acoustic analogy formulation. The FMM-BEM is implemented for the solution of acoustic scattering problems and the effects of non-uniform potential flows on acoustic scattering are investigated. The FMM-FWH is implemented for the solution of two and three-dimensional problems of sound propagation. The effects of flow convection and non-linear quadrupole sources are assessed through the study of sound generated by unsteady laminar flows. Finally, a hybrid methodology is applied for the investigation of airfoil noise. This study is important for the design of aerodynamic shapes such as wings and high-lift devices, as well as wind turbine blades, fans and propellers. The present investigation of airfoil self-noise generation and propagation concerns the broadband noise that arises from the interaction of turbulent boundary layers with the airfoil trailing edge and tonal noise that arises from vortex shedding generated by laminar boundary layers. Nearfield acoustic sources are computed using compressible large eddy simulation (LES) and acoustic predictions are performed by the FMM-FWH. Numerical simulations are conducted for a NACA0012 airfoil with tripped boundary layers and blunt rounded trailing edge at different Mach numbers and angles of incidence. The effects of non-linear quadrupole sources and convection are assessed. In order to validate the numerical solutions, flow simulation and acoustic prediction results are compared to experimental data available in the literature and excellent agreement is observed.

Development of Improved Surface Integral Methods for Jet Aeroacoustic Predictions

Development of Improved Surface Integral Methods for Jet Aeroacoustic Predictions PDF Author: Anthony Richard Pilon
Publisher:
ISBN:
Category :
Languages : en
Pages : 242

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Advanced Applications in Acoustics, Noise and Vibration

Advanced Applications in Acoustics, Noise and Vibration PDF Author: Frank Fahy
Publisher: CRC Press
ISBN: 1482289083
Category : Technology & Engineering
Languages : en
Pages : 656

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Book Description
Advanced Applications in Acoustics, Noise and Vibration provides comprehensive and up-to-date overviews of knowledge, applications and research activities in a range of topics that are of current interest in the practice of engineering acoustics and vibration technology. The thirteen chapters are grouped into four parts: signal processing, acoustic modelling, environmental and industrial acoustics, and vibration. Following on from its companion volume Fundamentals of Noise and Vibration this book is based partly on material covered in a selection of elective modules in the second semester of the Masters programme in 'Sound and Vibration Studies' of the Institute of Sound and Vibration Research at the University of Southampton, UK and partly on material presented in the annual ISVR short course 'Advanced Course in Acoustics, Noise and Vibration'.

Predicting Flow-Induced Acoustics at Near-Stall Conditions in an Automotive Turbocharger Compressor

Predicting Flow-Induced Acoustics at Near-Stall Conditions in an Automotive Turbocharger Compressor PDF Author: Roberto Navarro GarcĂ­a
Publisher: Springer
ISBN: 3319722484
Category : Technology & Engineering
Languages : en
Pages : 164

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Book Description
This thesis offers new insights into the fluid flow behavior of automotive centrifugal compressors operating under near-stall conditions. Firstly it discusses the validation of three-dimensional computational fluid dynamics (CFD) unsteady simulations against acoustic experimental measurements using an original procedure based on plane wave pressure decomposition. It then examines the configuration of the CFD cases, highlighting the key parameters needed for a successful calculation. Moreover, it describes both the compressor mean and unsteady flow field from best-efficiency to near-surge operating points. Lastly, it provides readers with explanations of the various phenomena that arise when the mass flow rate is reduced and the compressor is driven to poor and noisy performance. Written for students, researchers and professionals who want to improve their understanding of the complex fluid flow behavior in centrifugal compressors, the thesis offers valuable practical insights into reducing the acoustic emissions of turbochargers.