Download or read book A Generalized Finite Element Method for Solving the Helmholtz Equation in Two Dimensions with Minimal Pollution written by and published by . This book was released on 1994 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: When using the Galerkin FEM for solving the Helmholtz equation in two dimensions, the error of the corresponding solution differs substantially from the error of the best approximation, and this effect increases with higher wave number k. In this paper we will design a Generalized Finite Element Method (GFEM) for the Helmholtz equation such that the pollution effect is minimal. (AN).
Download or read book Generalized Finite Element Method for Helmholtz Equation written by Realino Hidajat and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents the Generalized Finite Element Method (GFEM) for the scalar Helmholtz equation, which describes the time harmonic acoustic wave propagation problem. We introduce several handbook functions for the Helmholtz equation, namely the planewave, wave-band, and Vekua functions, and we use these handbook functions to enrich the Finite Element space via the Partition of Unity Method to create the GFEM space. The enrichment of the approximation space by these handbook functions reduces the pollution effect due to wave number and we are able to obtain a highly accurate solution with a much smaller number of degrees-of-freedom compared with the classical Finite Element Method. The q-convergence of the handbook functions is investigated, where q is the order of the handbook function, and it is shown that asymptotically the handbook functions exhibit the same rate of exponential convergence. Hence we can conclude that the selection of the handbook functions from an admissible set should be dictated only by the ease of implementation and computational costs. Another issue addressed in this dissertation is the error coming from the artificial truncation boundary condition, which is necessary to model the Helmholtz problem set in the unbounded domain. We observe that for high q, the most significant component of the error is the one due to the artificial truncation boundary condition. Here we propose a method to assess this error by performing an additional computation on the extended domain using GFEM with high q.
Download or read book Multiscale Finite Element Method for Helmholtz Equation written by 黃楓南 and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Finite Element Method for Engineers written by Kenneth H. Huebner and published by John Wiley & Sons. This book was released on 2001-09-07 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eine Einführung in alle Aspekte der finiten Elemente, jetzt schon in der 4. Auflage! Geboten wird eine ausgewogene Mischung theoretischer und anwendungsorientierter Kapitel mit vielen Beispielen. Schwerpunkte liegen auf Anwendungen aus der Mechanik, dem Wärmetransport, der Elastizität sowie auf disziplinübergreifenden Problemen (Strömungen von Fluiden, Elektromagnetismus). Eine nützliche und zuverlässige Informationsquelle für Studenten und Praktiker!
Download or read book Advances in Electronics Communication and Computing written by Akhtar Kalam and published by Springer. This book was released on 2017-10-27 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compilation of research work in the interdisciplinary areas of electronics, communication, and computing. This book is specifically targeted at students, research scholars and academicians. The book covers the different approaches and techniques for specific applications, such as particle-swarm optimization, Otsu’s function and harmony search optimization algorithm, triple gate silicon on insulator (SOI)MOSFET, micro-Raman and Fourier Transform Infrared Spectroscopy (FTIR) analysis, high-k dielectric gate oxide, spectrum sensing in cognitive radio, microstrip antenna, Ground-penetrating radar (GPR) with conducting surfaces, and digital image forgery detection. The contents of the book will be useful to academic and professional researchers alike.
Download or read book The Finite Element Method Theory Implementation and Applications written by Mats G. Larson and published by Springer Science & Business Media. This book was released on 2013-01-13 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives an introduction to the finite element method as a general computational method for solving partial differential equations approximately. Our approach is mathematical in nature with a strong focus on the underlying mathematical principles, such as approximation properties of piecewise polynomial spaces, and variational formulations of partial differential equations, but with a minimum level of advanced mathematical machinery from functional analysis and partial differential equations. In principle, the material should be accessible to students with only knowledge of calculus of several variables, basic partial differential equations, and linear algebra, as the necessary concepts from more advanced analysis are introduced when needed. Throughout the text we emphasize implementation of the involved algorithms, and have therefore mixed mathematical theory with concrete computer code using the numerical software MATLAB is and its PDE-Toolbox. We have also had the ambition to cover some of the most important applications of finite elements and the basic finite element methods developed for those applications, including diffusion and transport phenomena, solid and fluid mechanics, and also electromagnetics.
Download or read book Finite Element Analysis of Acoustic Scattering written by Frank Ihlenburg and published by Springer Science & Business Media. This book was released on 2006-03-29 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: A cognitive journey towards the reliable simulation of scattering problems using finite element methods, with the pre-asymptotic analysis of Galerkin FEM for the Helmholtz equation with moderate and large wave number forming the core of this book. Starting from the basic physical assumptions, the author methodically develops both the strong and weak forms of the governing equations, while the main chapter on finite element analysis is preceded by a systematic treatment of Galerkin methods for indefinite sesquilinear forms. In the final chapter, three dimensional computational simulations are presented and compared with experimental data. The author also includes broad reference material on numerical methods for the Helmholtz equation in unbounded domains, including Dirichlet-to-Neumann methods, absorbing boundary conditions, infinite elements and the perfectly matched layer. A self-contained and easily readable work.
Download or read book A Finite Element Method for the Two dimensional Helmholtz Equation in Unbounded Regions written by Michael J. Scheidler and published by . This book was released on 1979 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Method on Nonmatching Meshes for the Helmholtz Equation written by Erkki Heikkola and published by . This book was released on 1995 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Elements and Approximation written by O. C. Zienkiewicz and published by Courier Corporation. This book was released on 2006-01-01 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: A powerful tool for the approximate solution of differential equations, the finite element is extensively used in industry and research. This book offers students of engineering and physics a comprehensive view of the principles involved, with numerous illustrative examples and exercises. Starting with continuum boundary value problems and the need for numerical discretization, the text examines finite difference methods, weighted residual methods in the context of continuous trial functions, and piecewise defined trial functions and the finite element method. Additional topics include higher order finite element approximation, mapping and numerical integration, variational methods, and partial discretization and time-dependent problems. A survey of generalized finite elements and error estimates concludes the text.
Download or read book A Finite Element Method for Problems Involving the Helmholtz Equation in Two Dimensional Exterior Regions written by Samuel Paul Marin and published by . This book was released on 1978 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Least squares Finite Element Method for Helmholtz Equation written by C. L. Chang and published by . This book was released on 1989 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Solution to the Helmholtz Equation with High Wave Number Part 1 The H Version of the FEM written by and published by . This book was released on 1993 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The h-version of the finite element method with piecewise linear approximation has been applied to solve a one-dimensional model problem for the Helmholtz equation. The main practical purpose of the investigation is to lay theoretical ground for safe rules of the thumb how to choose the mesh width of the FE-model depending on the wavenumber. In this context we present new results for stability and error estimation of the FE-solution. Following the analysis, numerical results are discussed. In a second paper we will study the h-p-method for Helmholtz problems.
Download or read book Finite Element Analysis written by Barna Szabó and published by John Wiley & Sons. This book was released on 1991-09-03 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the fundamentals of linear theory of finite elements, from both mathematical and physical points of view. Major focus is on error estimation and adaptive methods used to increase the reliability of results. Incorporates recent advances not covered by other books.
Download or read book A Two Level Finite Element Method and Its Application to the Helmholtz Equation written by Leopoldo P. Franca and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Methods written by Jonathan Whiteley and published by Springer. This book was released on 2017-01-26 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents practical applications of the finite element method to general differential equations. The underlying strategy of deriving the finite element solution is introduced using linear ordinary differential equations, thus allowing the basic concepts of the finite element solution to be introduced without being obscured by the additional mathematical detail required when applying this technique to partial differential equations. The author generalizes the presented approach to partial differential equations which include nonlinearities. The book also includes variations of the finite element method such as different classes of meshes and basic functions. Practical application of the theory is emphasised, with development of all concepts leading ultimately to a description of their computational implementation illustrated using Matlab functions. The target audience primarily comprises applied researchers and practitioners in engineering, but the book may also be beneficial for graduate students.
Download or read book Finite Element Methods and Their Applications written by Zhangxin Chen and published by Springer Science & Business Media. This book was released on 2005-06-23 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduce every concept in the simplest setting and to maintain a level of treatment that is as rigorous as possible without being unnecessarily abstract. Contains unique recent developments of various finite elements such as nonconforming, mixed, discontinuous, characteristic, and adaptive finite elements, along with their applications. Describes unique recent applications of finite element methods to important fields such as multiphase flows in porous media and semiconductor modelling. Treats the three major types of partial differential equations, i.e., elliptic, parabolic, and hyperbolic equations.
