Download or read book Transmission Line Matrix Modelling of Acoustic Waves with Application to Dynamic Boundary Problems written by Kieran Lynch and published by . This book was released on 1996 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling Room Acoustics Using Transmission Line Matrix Method written by Anirudh Prakhya and published by . This book was released on 2020-09-22 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of the project is to model room acoustics using Transmission Line Matrix Method (TLM). The method approximates acoustic wave propagation by Huygen's principle. It is best suited for equidistant nodes and fixed time steps coupled to the spatial distance of the nodes. The TLM method was applied to a one-dimensional (1-D) case of an air column. The results were validated using a model generated by Finite Difference Method (FDM). The results indicate no spurious peaks or built up errors. Accuracy of the plot could be made more fine by varying mesh size and propagation velocity while keeping time-step constant. In the two-dimensional (2-D) TLM model of a square plane considered on the surface of water, new issues were observed. The simulation creates dispersion effects. It was observed that this effect occurs when the wave pattern is sharp beyond a particular level. After making corrections, the TLM method was applied to other 2-D cases. In modelling moving sources, two methods were explored. The first implied the direct movement of the source by one node for some pre-defined number of time-steps i.e. moving source at some finite value of speed. The results indicate distortion in the radial propagation and sharp ends at the source. The second method requires dividing the intervening space into n sub-units and taking the corresponding weighted mean of the amplitudes at the two nodes. The obtained results were explained using Doppler effect. The TLM method was extended to model acoustic beam-steering using phased arrays. The applications of this are usually in radio communications. A rigid wall was used as the reflector. The pulses coming from each of the five sources were kept in a temporary store and at the next iteration, these values were used as the incident pulses. Thus superposing the effect of the five sources at each node in the grid. The beam can be propagated in a specific direction by varying the phase difference. The boundary conditions were varied and perfectly reflecting, perfectly absorbing and partially absorbing-partially reflecting boundaries were considered. The reflection coefficient values used at the boundaries are as follows: ρ = 1 for rigid walls, ρ = -1 for open ends and ρ = 0 for impedance boundaries. By varying the values of frequency, standing waves were generated in 1-D and 2-D cases. In 2-D waves were captured at the transition state. Three dimensional (3-D) room acoustics was simulated using TLM. Modelling in 3-D was lot more different from the rest as large computation time and computational power was required. There are numerous methods available to model 3-D case like triangular meshing, Cartesian meshing, tetrahedral meshing etc. Cartesian method was used for this project as it is the natural extension of 2-D TLM code. The wave propagation was captured on three perpendicular planes parallel to the coordinate planes. Open, rigid and impedance boundaries were also modelled. The results were found to be satisfactory. From the results obtained, it can be concluded that TLM is equivalent to FDM in terms of its usefulness. Despite the computational time and power being higher than FDM, the results are more accurate and the simulation itself runs without any hindrances. Compared to the problems of instability or very high noise, that are frequently encountered in FDM, TLM stands as the better solution.
Download or read book Transmission Line Matrix Modelling of Acoustic Waves with Applications to Active Noise Control in Exhausts and Ducts written by Fergus Cavanagh and published by . This book was released on 1994 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Acoustics and Its Environmental Applications II written by C. A. Brebbia and published by Witpress. This book was released on 1997 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the Second International Conference on Computational Acoustics and its Environmental Applications.
Download or read book Transmission Line Matrix TLM in Computational Mechanics written by Donard de Cogan and published by CRC Press. This book was released on 2005-11-01 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The finite element method reigns as the dominant technique for modeling mechanical systems. Originally developed to model electromagnetic systems, the Transmission Line Matrix (TLM) method proves to match, and in some cases exceed, the effectiveness of finite elements for modeling several types of physical systems. Transmission Line Matrix in Computational Mechanics provides a tutorial approach to applying TLM for modeling mechanical and other physical systems. Transmission Line Matrix in Computational Mechanics begins with the history of TLM, an introduction to the theory using mechanical engineering concepts, and the electromagnetic basics of TLM. The authors then demonstrate the theory for use in acoustic propagation, along with examples of MATLAB® code. The remainder of the book explores the application of TLM to problems in mechanics, specifically heat and mass transfer, elastic solids, simple deformation models, hydraulic systems, and computational fluid dynamics. A discussion of state-of-the-art techniques concludes the book, offering a look at the current research undertaken by the authors and other leading experts to overcome the limitations of TLM in applying the method to diverse types of systems. This valuable reference introduces students, engineers, and researchers to a powerful, accurate, and stable alternative to finite elements, providing case studies and examples to reinforce the concepts and illustrate the applications.
Download or read book The Scaled Boundary Finite Element Method written by Chongmin Song and published by John Wiley & Sons. This book was released on 2018-06-19 with total page 775 pages. Available in PDF, EPUB and Kindle. Book excerpt: An informative look at the theory, computer implementation, and application of the scaled boundary finite element method This reliable resource, complete with MATLAB, is an easy-to-understand introduction to the fundamental principles of the scaled boundary finite element method. It establishes the theory of the scaled boundary finite element method systematically as a general numerical procedure, providing the reader with a sound knowledge to expand the applications of this method to a broader scope. The book also presents the applications of the scaled boundary finite element to illustrate its salient features and potentials. The Scaled Boundary Finite Element Method: Introduction to Theory and Implementation covers the static and dynamic stress analysis of solids in two and three dimensions. The relevant concepts, theory and modelling issues of the scaled boundary finite element method are discussed and the unique features of the method are highlighted. The applications in computational fracture mechanics are detailed with numerical examples. A unified mesh generation procedure based on quadtree/octree algorithm is described. It also presents examples of fully automatic stress analysis of geometric models in NURBS, STL and digital images. Written in lucid and easy to understand language by the co-inventor of the scaled boundary element method Provides MATLAB as an integral part of the book with the code cross-referenced in the text and the use of the code illustrated by examples Presents new developments in the scaled boundary finite element method with illustrative examples so that readers can appreciate the significant features and potentials of this novel method—especially in emerging technologies such as 3D printing, virtual reality, and digital image-based analysis The Scaled Boundary Finite Element Method: Introduction to Theory and Implementation is an ideal book for researchers, software developers, numerical analysts, and postgraduate students in many fields of engineering and science.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1979 with total page 556 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 1994 with total page 880 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 The Shock and Vibration Digest written by and published by . This book was released on 1988 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2005 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Noise and Vibration Control written by Malcolm J. Crocker and published by John Wiley & Sons. This book was released on 2007-10-05 with total page 1594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two of the most acclaimed reference works in the area of acoustics in recent years have been our Encyclopedia of Acoustics, 4 Volume set and the Handbook of Acoustics spin-off. These works, edited by Malcolm Crocker, positioned Wiley as a major player in the acoustics reference market. With our recently published revision of Beranek & Ver's Noise and Vibration Control Engineering, Wiley is a highly respected name in the acoustics business. Crocker's new handbook covers an area of great importance to engineers and designers. Noise and vibration control is one largest areas of application of the acoustics topics covered in the successful encyclopedia and handbook. It is also an area that has been under-published in recent years. Crocker has positioned this reference to cover the gamut of topics while focusing more on the applications to industrial needs. In this way the book will become the best single source of need-to-know information for the professional markets.
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 Energy Research Abstracts written by and published by . This book was released on 1985 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1970 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technology for Large Space Systems written by and published by . This book was released on 1986 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory and Practice of Geophysical Data Inversion written by Andreas Vogel and published by Vieweg+Teubner Verlag. This book was released on 2012-12-06 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contributions to this volume cover a wide spectrum of recent developments in geophysical data inversion, including basic mathematics and general theory, numerical methods, as well as computer implementation of algorithms. Most of the papers are motivated by problems arising from geophysical research and applications both on a global scale and with respect to local geophysical surveys, underlining the increasing importance of geophysical exploration methods in various fields, such as structural geology, prospecting for mineral and energy resources, hydro geology, geotechnology, environmental protection and archaeology. The first section of the book deals with basic mathematics and general theory underlying geophysical data inversion. Papers presented here are concerned with stabilization algorithms to solve ill-posed inverse problems, sensitivity of kernel function estimations to random data errors and reduction of errors in inverse modelling of response functions by linear constraints, numerical procedures for approximating the solution to boundary value problems, accuracy and stability of inverse ill-posed problems constituted by problems of moments, and fast Fourier transforms for solving potential field problems. The second section contains papers on gravity and magnetics, dealing with the solvability of the inverse gravimetric problem for sources represented by point masses and other elementary, solution of the inverse problem in cases of nonuniformly distributed data as obtained by palaeomagnetic studies, satellite observations, and surface projections of buried archaeological targets by inverse filtering of geomagnetic data.
