Outdoor Sound Propagation Modelling in Complex Environments: Recent Developments in the Parabolic Equation Method PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Outdoor Sound Propagation Modelling in Complex Environments: Recent Developments in the Parabolic Equation Method PDF full book. Access full book title Outdoor Sound Propagation Modelling in Complex Environments: Recent Developments in the Parabolic Equation Method by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17
Get Book Here
Book Description
In complex environments the modelling of outdoor sound propagation implies to take into account the mixed influence of ground characteristics (topography, obstacles, impedance, etc.) and atmospheric conditions (refraction and turbulence). During the last decade significant progress has been made in the modelling of sound propagation over distances ranging from hundreds meters to kilometres, and the agreement between calculated and measured fields has been greatly improved. New developments appear in the parabolic-equation method. In this paper we present a method which evaluates the propagation of an acoustic wave above uneven terrains including realistic meteorological parameters. In our approach the effects of the topography are modelled using appropriate rotated co-ordinates systems in order to treat the non-flat ground as a succession of flat domains. We also examine the influence of scale resolution on numerical simulation of long range sound propagation through the turbulent atmosphere. Currently, we generate the turbulence using a Random Fourier Modes technique, such that the turbulent fluctuation at any point in the medium (either scalar or vectorial in nature) is calculated from the sum of a chosen number of modes. Our model of outdoors sound propagation is validated both with classical numerical benchmark cases and recent outdoor experiments.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17
Get Book Here
Book Description
In complex environments the modelling of outdoor sound propagation implies to take into account the mixed influence of ground characteristics (topography, obstacles, impedance, etc.) and atmospheric conditions (refraction and turbulence). During the last decade significant progress has been made in the modelling of sound propagation over distances ranging from hundreds meters to kilometres, and the agreement between calculated and measured fields has been greatly improved. New developments appear in the parabolic-equation method. In this paper we present a method which evaluates the propagation of an acoustic wave above uneven terrains including realistic meteorological parameters. In our approach the effects of the topography are modelled using appropriate rotated co-ordinates systems in order to treat the non-flat ground as a succession of flat domains. We also examine the influence of scale resolution on numerical simulation of long range sound propagation through the turbulent atmosphere. Currently, we generate the turbulence using a Random Fourier Modes technique, such that the turbulent fluctuation at any point in the medium (either scalar or vectorial in nature) is calculated from the sum of a chosen number of modes. Our model of outdoors sound propagation is validated both with classical numerical benchmark cases and recent outdoor experiments.
Author: Thomas Leissing
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
This research aims at developing and validating a numerical model for the study of blast wave propagation over large distances and over urban environments. The approach consists in using the Nonlinear Parabolic Equation (NPE) model as a basis. The model is then extended to handle various features of sound propagation outdoors (non-flat ground topographies, porous ground layers, etc.). The NPE is solved using the finite-difference method and is proved to be in good agreement with other numerical methods. This deterministic model is then used as a basis for the construction of a stochastic model for sound propagation over urban environments. Information Theory and the Maximum Entropy Principle enable the construction of a probabilistic model of uncertainties, which takes into account the variability of the urban environment within the NPE model. Reference results are obtained with an exact numerical method and allow us to validate the theoretical developments and the approach used.
Author: Whitney L. Coyle
Publisher:
ISBN:
Category :
Languages : en
Pages : 146
Get Book Here
Book Description
Author: Keith Attenborough
Publisher: CRC Press
ISBN: 0429894821
Category : Technology & Engineering
Languages : en
Pages : 579
Get Book Here
Book Description
The second edition of Predicting Outdoor Sound is an up-to-date reference on the propagation of sound close to the ground and its prediction. New content includes comparisons between predictions and data for road traffic, railway and wind turbine noise; descriptions of source characteristics in the HARMONOISE model; propagation over rough seas, parallel low walls, and lattices; outlines of numerical methods; gabion (caged stones) and sonic crystal noise barriers; meteorological effects on noise barrier performance; and the prediction requirements for auralization. The book brings together relevant theories, prediction schemes, and data, thereby providing a basis for determining what model or scheme might be applicable for any situation. It also offers a background on useful analytical approximations and the restrictions, as well as difficulties and limitations associated with engineering prediction schemes. The text should be of considerable interest to researchers in outdoor sound propagation and, more generally, it should provide a comprehensive primer on the topic for lecturers, consultants and students in acoustics and noise control.
Author: Marta Galindo Arranz
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Finn Jensen
Publisher:
ISBN:
Category :
Languages : en
Pages : 50
Get Book Here
Book Description
The parabolic equation method (PE method) is the latest major development in the field of acoustic modelling. A detailed description of the derivation of the parabolic equation from the wave equation is given together with a description of a marching solution technique based on Fast Fourier Transforms (FFT). Limitations on the method in terms of allowable step length in range, number of FFT points to be used, and restrictions on pressure field behaviour in order to obtain a stable solution, are mentioned. Furthermore, numerical examples of propagation predictions are given for both shallow and deep water cases, with and without bottom absorption, and for both range-dependent and range-independent environmental conditions.
Author: Marta Galindo Arranz
Publisher:
ISBN:
Category :
Languages : en
Pages : 163
Get Book Here
Book Description
Author: Acoustical Society of America
Publisher:
ISBN:
Category : Acoustical engineering
Languages : en
Pages : 1114
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 1116
Get Book Here
Book Description
Author: Thomas Rossing
Publisher: Springer Science & Business Media
ISBN: 0387304460
Category : Science
Languages : en
Pages : 1179
Get Book Here
Book Description
This is an unparalleled modern handbook reflecting the richly interdisciplinary nature of acoustics edited by an acknowledged master in the field. The handbook reviews the most important areas of the subject, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, including computer recognition and synthesis of speech, physiological acoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. An accompanying CD-ROM contains audio and video files.
