Computational Atmospheric Acoustics


Book Description

Noise from cars, trains, and aeroplanes can be heard at large distances from the source. Accurate predictions of the loudness of the noise require accurate computations of sound propagation in the atmosphere. This book describes models that can be used for these computations. The models take into account complex effects of the atmosphere and the ground surface on sound waves, including the effects of wind and temperature distributions, atmospheric turbulence, irregular terrain, and noise barriers. The main text of the book focuses on physical effects in atmospheric acoustics. The effects are illustrated by many numerical examples. The main text requires a very limited mathematical background from the reader; detailed mathematical descriptions of the models, developed from the basic principles of acoustics, are presented in appendices. Models for moving media are compared with models that are based on the effective sound speed approach. Both two-dimensional models and three-dimensional models are presented. As meteorological effects play an important role in atmospheric acoustics, selected topics from boundary layer meteorology and the theory of turbulence are also presented.




Computational Simulation in Architectural and Environmental Acoustics


Book Description

This book reviews a variety of methods for wave-based acoustic simulation and recent applications to architectural and environmental acoustic problems. Following an introduction providing an overview of computational simulation of sound environment, the book is in two parts: four chapters on methods and four chapters on applications. The first part explains the fundamentals and advanced techniques for three popular methods, namely, the finite-difference time-domain method, the finite element method, and the boundary element method, as well as alternative time-domain methods. The second part demonstrates various applications to room acoustics simulation, noise propagation simulation, acoustic property simulation for building components, and auralization. This book is a valuable reference that covers the state of the art in computational simulation for architectural and environmental acoustics.




Atmospheric Acoustics


Book Description

This book concisely expounds the fundamental concepts, phenomena, theories and procedures in a complete and systematic sense. In this book, not only almost all the important achievements from predecessors but also the contributions from the author himself have been summed up profoundly. Starting from the derivation of fundamental equations, various classical acoustical phenomena such as reflection, refraction, scattering diffraction and absorption in atmosphere, as well as the influences of gravitation and rotation of the earth on the behaviors of different atmospheric waves including acoustic waves, have been discussed in viewpoints of wave acoustics and geometrical acoustics respectively. The recent developments of several computation methods in the field of atmospheric acoustics have been introduced in some detail. As for the application aspects, atmospheric remote sensing has been discussed from the angle of inverse problems.




Computational Ocean Acoustics


Book Description

Senior level/graduate level text/reference presenting state-of-the- art numerical techniques to solve the wave equation in heterogeneous fluid-solid media. Numerical models have become standard research tools in acoustic laboratories, and thus computational acoustics is becoming an increasingly important branch of ocean acoustic science. The first edition of this successful book, written by the recognized leaders of the field, was the first to present a comprehensive and modern introduction to computational ocean acoustics accessible to students. This revision, with 100 additional pages, completely updates the material in the first edition and includes new models based on current research. It includes problems and solutions in every chapter, making the book more useful in teaching (the first edition had a separate solutions manual). The book is intended for graduate and advanced undergraduate students of acoustics, geology and geophysics, applied mathematics, ocean engineering or as a reference in computational methods courses, as well as professionals in these fields, particularly those working in government (especially Navy) and industry labs engaged in the development or use of propagating models.




Springer Handbook of Acoustics


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.




Theoretical And Computational Acoustics '95


Book Description

This conference provided a forum for active researchers to discuss the state-of-the-art in theoretical and computational acoustics. Topics covered fluid/elastic interface-theoretical and computational aspects with applications, seismic waves and earthquake studies, modeling, theoretical and computational aspects for multidimensional wave propagation, methods for computational acoustics, structural acoustics, scattering and inverse problems, solutions to acoustic problems by supercomputers and parallel processing, and application of neural networks to acoustics.




Atmospheric Acoustic Remote Sensing


Book Description

Sonic Detection and Ranging (SODAR) systems and Radio Acoustic Sounding Systems (RASS) use sound waves to determine wind speed, wind direction, and turbulent character of the atmosphere. They are increasingly used for environmental and scientific applications such as analyzing ground-level pollution dispersion and monitoring conditions affecting wind energy generation. However, until now there have been no reliable references on SODAR and RASS for practitioners in the field as well as non-experts who wish to understand and implement this technology to their own applications. Authored by an internationally known expert in the design and use of SODAR/RASS technology, Atmospheric Acoustic Remote Sensing: Principles and Applications systematically explains the underlying science, principles, and operational aspects of acoustic radars. Abundant diagrams and figures, including eight pages of full-color images, enhance clear guidelines and tools for handling calibration, error, equipment, hardware, sampling, and data analysis. The final chapter explores applications in environmental research, boundary layer research, wind power and loading, complex terrain, and sound speed profiles. Atmospheric Acoustic Remote Sensing offers SODAR and RASS users as well as general remote sensing practitioners, environmental scientists, and engineers a straightforward guide for using SODARs to perform wind measurements and data analysis for scientific, environmental, or alternative monitoring applications.




Computational Aeroacoustics


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).




Acoustics


Book Description

Essential concepts, theory and models of linear acoustics for engineers. This book introduces the basic concepts, theory and models of linear acoustics for engineers. Part one develops the theoretical framework (wave equations, Fourier theory, Helmholtz equation) and introduces key concepts (pressure, velocity, impedance, intensity, power, sound levels). Part two proposes a systematic review of the fundamental physical mechanisms of acoustics and discusses the associated mathematical models: reflection, absorption, resonance, guided propagation, radiation, diffraction, refraction, propagation in dissipative media, convected propagation, atmospheric propagation, fluid-structure interaction, sound transmission and insulation.




Handbook of Signal Processing in Acoustics


Book Description

The Handbook of Signal Processing in Acoustics brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of the subject. It brings the key issues from both acoustics and signal processing into perspective and is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.




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