An analysis of the major topics in sound suppression and noise control for the analysis and design of acoustical mufflers, air conditioning and ventilation duct work. Both fundamentals and the latest technology are discussed, with an emphasis on applications.

Fully updated second edition of the premier reference book on muffler and lined duct acoustical performance Engine exhaust noise pollutes the street environment and ventilation fan noise enters dwellings along with fresh air. People have become conscious of their working environment. Governments of most countries have responded to popular demand with mandatory restrictions on sound emitted by automotive engines, and a thorough knowledge of acoustics of ducts and mufflers is needed for the design of efficient muffler configurations. This fully updated Second Edition of Acoustics of Ducts and Mufflers deals with propagation, reflection and dissipation/absorption of sound along ducts/pipes/tubes, area discontinuities, perforated elements and absorptive linings that constitute the present-day mufflers and silencers designed to control noise of exhaust and intake systems of automotive engines, diesel-generator sets, compressors and HVAC systems. It includes equations, figures, tables, references, and solved examples and unsolved exercises with answers, so it can be used as a text book as well as a reference book. It also offers a complete presentation and analysis of the major topics in sound suppression and noise control for the analysis and design of acoustical mufflers, air conditioning and ventilation duct work. Both the fundamentals and the latest technology are discussed, with an emphasis on applications. Deals with reactive mufflers, dissipative silencers, the frequency-domain approach, and the time-domain approach. Fully updated second edition of the premier reference book on muffler and lined duct acoustical performance, in one complete volume Presents original new research on topics including baffle silencers and louvers, 3D analytical techniques, and flow-acoustic analysis of multiply-connected perforated-element mufflers Includes a general design procedure to help muffler designers in the automotive industry, exhaust noise being a major component of automobile and traffic noise pollution Written by an expert with four decades’ experience in teaching to graduate students, publishing extensively in reputed international journals, and consulting with industry for noise control as well as designing for quietness

Recent Researches in Engineering Sciences

This book gives readers a working knowledge of vehicle vibration, noise, and sound quality. The knowledge it imparts can be applied to analyze real-world problems and devise solutions that reduce vibration, control noise, and improve sound quality in all vehicles—ground, aerospace, rail, and marine. Also described and illustrated are fundamental principles, analytical formulations, design approaches, and testing techniques. Whole vehicle systems are discussed, as are individual components. The latest measurement and computation tools are presented to help readers with vehicle noise, vibration, and sound quality issues. The book opens with a presentation of the fundamentals of vibrations and basic acoustic concepts, as well as how to analyze, test, and control noise and vibrations. The next 2 chapters delve into noise and vibrations that emanate from powertrains, bodies, and chassis. The book finishes with an in-depth discussion on evaluating noise, vibration, and sound quality, giving readers a solid grounding in the fundamentals of the subject, as well as information they can apply to situations in their day-to-day work. This book is intended for: •Upper-level undergraduate and graduate students of vehicle engineering •Practicing engineers •Designers •Researchers •Educators

Optimization problems arising in practice usually contain several random parameters. Hence, in order to obtain optimal solutions being robust with respect to random parameter variations, the mostly available statistical information about the random parameters should be considered already at the planning phase. The original problem with random parameters must be replaced by an appropriate deterministic substitute problem, and efficient numerical solution or approximation techniques have to be developed for those problems. This proceedings volume contains a selection of papers on modelling techniques, approximation methods, numerical solution procedures for stochastic optimization problems and applications to the reliability-based optimization of concrete technical or economic systems.

Se recoge en este libro una selección de las contribuciones presentadas a varios seminarios científicos que se organizaron en el Instituto de Acústica del CSIC durante los años 2004 y 2005. Esas contribuciones tratan un amplio abanico de temas, desde las estrategias para medir y controlar el ruido en la ciudad de Madrid hasta la técnica de toma de imágenes con fines médicos basada en el comportamiento elástico de los tejidos humanos. Otros temas -como los sistemas de sensores de onda acústica de superficie, el control de ruido activo, o los dispositivos para la inspección sanitaria de productos de uso cotidiano por medio de ultrasonidos- constituyen buenos ejemplos de la utilización de sistemas acústicos en el mundo industrial.

This book delivers a comprehensive and up-to-date treatment of practical applications of metamaterials, structured media, and conventional porous materials. With increasing levels of urbanization, a growing demand for motorized transport, and inefficient urban planning, environmental noise exposure is rapidly becoming a pressing societal and health concern. Phononic and sonic crystals, acoustic metamaterials, and metasurfaces can revolutionize noise and vibration control and, in many cases, replace traditional porous materials for these applications. In this collection of contributed chapters, a group of international researchers reviews the essentials of acoustic wave propagation in metamaterials and porous absorbers with viscothermal losses, as well as the most recent advances in the design of acoustic metamaterial absorbers. The book features a detailed theoretical introduction describing commonly used modelling techniques such as plane wave expansion, multiple scattering theory, and the transfer matrix method. The following chapters give a detailed consideration of acoustic wave propagation in viscothermal fluids and porous media, and the extension of this theory to non-local models for fluid saturated metamaterials, along with a description of the relevant numerical methods. Finally, the book reviews a range of practical industrial applications, making it especially attractive as a white book targeted at the building, automotive, and aeronautic industries.

The noise, vibration, and harshness (NVH), also known as noise and vibration (N&V), is a critical feature for customers to assess the performance and quality of vehicles. NVH characteristics are higher among factors that customers use to judge the vehicle's quality.This book sets out to introduce the basic concepts, principles, and applications of the NVH development and refi nement of Battery Electric Vehicles (BEV), Hybrid Electric Vehicles (HEV), and Fuel Cell Electric Vehicles. Each type comes with its own set of challenges.

Since the early seventies, the development of the automobile has been characterized by a steady increase in the deploymnet of onboard electronics systems and software. This trend continues unabated and is driven by rising end-user demands and increasingly stringent environmental requirements. Today, almost every function onboard the modern vehicle is electronically controlled or monitored. The software-based implementation of vehicle functions provides for unparalleled freedoms of concept and design. However, automobile development calls for the accommodation of contrasting prerequisites – such as higher demands on safety and reliability vs. lower cost ceilings, longer product life cycles vs. shorter development times – along with growing proliferation of model variants. Automotive Software Engineering has established its position at the center of these seemingly conflicting opposites. This book provides background basics as well as numerous suggestions, rare insights, and cases in point concerning those processes, methods, and tools that contribute to the surefooted mastery of the use of electronic systems and software in the contemporary automobile.