Download or read book Numerical Simulations in Room Acoustics Using Direct Coupling Techniques and Finite Elements written by Martina Pospiech and published by Logos Verlag Berlin GmbH. This book was released on 2012 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a coupling approach for time-harmonic problems in linear room acoustics. Therein the closed acoustic system is subdivided into air, sound source and different boundary components. The sound field of each air component is approximated with the help of modal basis functions and continuous transitions between single components are enabled by enforcing coupling conditions. Coupling to realistic boundary conditions is realized by wavenumber- and frequency-dependent impedance functions for plate-like sound absorbers. Afterwards the solution is computed by minimizing the energy based on Hamilton's Principle. For computing the basis functions and the energies of the components the Spectral Finite Element Method and the adapted Patch Recovery Method are applied. Finally numerical benchmark-simulations show the applications of this coupling approach.

Download or read book Numerical Simulation of Structural Acoustics Using Coupled Finite Element and Boundary Element Techniques written by Debashis Basu and published by . This book was released on 1997 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Wave and Ray Based Room Acoustic Simulations of Small Rooms written by Marc Aretz and published by Logos Verlag Berlin GmbH. This book was released on 2012 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present thesis establishes a complete framework for the combination of finite element and classical ray based acoustic simulations in small rooms and discusses the inherent challenges and limitations including all aspects of sound generation, sound reflection and sound reception. In this context, the thesis gives detailed guidelines for the best-possible determination of all necessary input data for both simulation domains. The overall potential of the presented combined approach is assessed by conducting extensive objective and subjective comparisons of measurement and simulation results for three types of acoustically relevant small spaces (a scale-model reverberation room, a recording studio and two different car passenger compartments).

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Journal of the Acoustical Society of America written by Acoustical Society of America and published by . This book was released on 2006 with total page 1360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Finite Element and Boundary Methods in Structural Acoustics and Vibration written by Noureddine Atalla and published by CRC Press. This book was released on 2017-07-26 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique and in-depth presentation of the finite element method (FEM) and the boundary element method (BEM) in structural acoustics and vibrations, this book illustrates the principles using a logical and progressive methodology, which leads to a thorough understanding of their physical and mathematical principles and their implementation to solve a wide range of problems in structural acoustics and vibration. This book helps readers to understand the principles, use of the FEM, and the BEM in structural acoustics and vibrations.

Download or read book Building Performance Analysis written by Pieter de Wilde and published by John Wiley & Sons. This book was released on 2018-07-23 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores and brings together the existent body of knowledge on building performance analysis Shortlisted in the CIBSE 2020 Building Performance Awards Building performance is an important yet surprisingly complex concept. This book presents a comprehensive and systematic overview of the subject. It provides a working definition of building performance, and an in-depth discussion of the role building performance plays throughout the building life cycle. The book also explores the perspectives of various stakeholders, the functions of buildings, performance requirements, performance quantification (both predicted and measured), criteria for success, and the challenges of using performance analysis in practice. Building Performance Analysis starts by introducing the subject of building performance: its key terms, definitions, history, and challenges. It then develops a theoretical foundation for the subject, explores the complexity of performance assessment, and the way that performance analysis impacts on actual buildings. In doing so, it attempts to answer the following questions: What is building performance? How can building performance be measured and analyzed? How does the analysis of building performance guide the improvement of buildings? And what can the building domain learn from the way performance is handled in other disciplines? Assembles the current body of knowledge on building performance analysis in one unique resource Offers deep insights into the complexity of using building performance analysis throughout the entire building life cycle, including design, operation and management Contributes an emergent theory of building performance and its analysis Building Performance Analysis will appeal to the building science community, both from industry and academia. It specifically targets advanced students in architectural engineering, building services design, building performance simulation and similar fields who hold an interest in ensuring that buildings meet the needs of their stakeholders.

Download or read book Coupling of Numerical and Statistical Methods in Acoustics written by Cristina Díaz Cereceda and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Problems in the field of vibroacoustics can be modelled in two fundamental ways. On the one hand, they can be addressed in a deterministic way, using numerical methods like the Finite Element Method. On the other hand, statistical methods such as SEA (Statistical Energy Analysis) can be used. Numerical methods are useful for cases with complex geometries but imply a high computational cost for the calculation at high frequencies, especially when working in large domains. They also provide detailed vibration and pressure fields, which are not required by acoustic regulations since they only consider averaged values. Statistical methods are suitable for high frequencies. They deal directly with averaged energies but require specific parameters of power transmission, like internal loss factors and coupling loss factors, whose values can not be calculated analytically for complex geometries. In this work both techniques are coupled so that necessary parameters for the SEA are obtained using a deterministic analysis. In the deterministic approach the Galerkin formulation is used to solve the dynamic problem in its weak form, with the eigenfunctions of the structural elements as the bases of functions used to express the vibration field. Then, a study of the different ways of estimating the coupling loss factor between two subsystems once the deterministic results are obtained is presented, with a discussion of their advantages and disadvantages. The described technique is applied to estimate the coupling loss factors in different configurations consisting of two plates connected with different devices. The obtained results are compared with existing approximated expressions and the good performance of the method is verified. Moreover, the estimated parameters are used to solve larger and more complex systems with SEA. Their results and computational costs are compared with those of the numerical solutions of the same problems. Obtained results differ slightly depending on the technique used for the estimation of the coupling loss factor but provide good trends in general. Therefore, this study shows the potential of combining the deterministic approach (and numerical methods) with the statistical approach in order to solve realistic vibroacoustic problems in the whole frequency range, stressing the differences between the various ways of estimating the coupling loss factor.

Download or read book New Advances in Modal Synthesis of Large Structures Non linear Damped and Non deterministic Cases written by Louis Jezequel and published by CRC Press. This book was released on 1997-01-01 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modal analysis of the structures appears to be an essential tool to master their dynamic behaviour. Particularly, the modal synthesis methods combined with the updating technics of the Finite Element models lead to the definition of strategies peculiarly efficient. At present, several developments are being carried out in order to spread these procedures to the latest requirements in structural dynamics: Vibro-acoustic . behaviour; Stochastic approach; Non-linear analysis; Introduction of composite materials. The target of the MV2 International Conference was to take stock of the new methods suggested and to assess their effectiveness. The interest in this book is to gather original works that rely on high-level approaches although these works are clearly intended to industrual applications.

Download or read book Noise news International written by and published by . This book was released on 1995 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Boundary Element Method in Acoustics written by Stephen Kirkup and published by Stephen Kirkup. This book was released on 1998 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coupling of Structural Dynamic and Acoustic Analyses Using the Fem and Bem written by Xin Han and published by . This book was released on 2012 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Noise from structural vibration is a major consideration in the design and manufacturing of a product, such as an automobile, airplane, and other consumer goods. Acoustic simulation is an important step to optimize the performance of many new products early in the design stage rather than correcting the mistakes afterwards. Effective and efficient numerical modeling and simulation methods will be important tools for noise prediction during the design stage of products. This thesis work focuses on integrating the numerical methods in the prediction of noise from vibrating structures. To calculate the sound radiated from a vibrating structure, both a structural dynamic problem and an acoustic wave problem should be considered. In this study, the finite element method (FEM) is chosen for the structural dynamic analysis in order to calculate the natural frequencies and harmonic responses of the structure. The boundary element method (BEM) is used in the acoustic analysis of the structure to calculate the radiated sound field. In the BEM, only the surface of a sound radiating structure is discretized and the simulation of sound fields in unbounded domains is easy, yielding an efficient mesh generation and preprocessing. To couple the FEM analysis with the BEM analysis, a computer program, or translation code, is developed for mapping the model and velocity boundary condition (BC) for the acoustic analysis from the results of the dynamic analysis. Several element types in the FEM using the software ABAQUS (r) are implemented in the translation code and their performances are studied. Different BEM solvers in the software FastBEM Acoustics (r) developed earlier at the University of Cincinnati (UC) and based on the fast multipole method (FMM), the adaptive cross approximation (ACA) method and the fast conventional BEM are selected in this study. The correctness and feasibility of the developed code are verified using a pulsating sphere model and a vibrating plate model. Numerical results and analytical data are found to be in good agreement using the developed translation code. As a large-scale and practical application, a wind turbine model is also used to study the noise propagation on the ground due to the vibration of the turbine structure and the rotation of turbine blades. It is found that the coupled analysis with the FEM and BEM can model the noise prediction of large-scale structures effectively and efficiently.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Virtual Acoustics and 3 D Sound in Multimedia Signal Processing written by Jyri Huopaniemi and published by . This book was released on 1999 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: