Download or read book High order Discontinuous Galerkin Methods for Incompressible Flows written by Adeline de Villardi de Montlaur and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Order Methods for Incompressible Fluid Flow written by M. O. Deville and published by Cambridge University Press. This book was released on 2002-08-15 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description

Download or read book A High Order Discontinuous Galerkin Method for 2D Incompressible Flows written by Jian-Guo Liu and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A High Order Discontinuous Galerkin for 2D Incompressible Flows written by Institute for Computer Applications in Science and Engineering. (ICASE) and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High order Discontinuous Galerkin Methods for Incompressible Flows written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquesta tesi doctoral proposa formulacions de Galerkin discontinu (DG) dalt ordre per fluxos viscosos incompressibles. Es desenvolupa un nou mètode de DG amb penalti interior (IPM-DG), que condueix a una forma feble simètrica i coerciva pel terme de difusió, i que permet assolir una aproximació espacial dalt ordre. Aquest mètode saplica per resoldre les equacions de Stokes i Navier-Stokes. Lespai daproximació de la velocitat es descompon dins de cada element en una part solenoidal i una altra irrotacional, de manera que es pot dividir la forma dèbil IPM-DG en dos problemes desacoblats. El primer permet el càlcul de les velocitats i de les pressions híbrides, mentre que el segon calcula les pressions en linterior dels elements. Aquest desacoblament permet una reducció important del número de graus de llibertat tant per velocitat com per pressió. Sintrodueix també un paràmetre extra de penalti resultant en una formulació DG alternativa per calcular les velocitats solenoidales, on les pressions no apareixen. Les pressions es poden calcular com un post-procés de la solució de les velocitats. Es contemplen altres formulacions DG, com per exemple el mètode Compact Discontinuous Galerkin, i es comparen al mètode IPM-DG. Es proposen mètodes implícits de Runge-Kutta dalt ordre per problemes transitoris incompressibles, permetent obtenir esquemes incondicionalment estables i amb alt ordre de precisió temporal. Les equacions de Navier-Stokes incompressibles transitòries sinterpreten com un sistema de Equacions Algebraiques Diferencials, és a dir, un sistema dequacions diferencials ordinàries corresponent a la equació de conservació del moment, més les restriccions algebraiques corresponent a la condició dincompressibilitat. Mitjançant exemples numèrics es mostra l'aplicabilitat de les metodologies proposades i es comparen la seva eficiència i precisió. ----------------------------------------------------------------------------------------------------- ABSTRACT This PhD thesis.

Download or read book Discontinuous Galerkin Methods written by Bernardo Cockburn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of finite element methods, the Discontinuous Galerkin Methods (DGM), has been under rapid development recently and has found its use very quickly in such diverse applications as aeroacoustics, semi-conductor device simula tion, turbomachinery, turbulent flows, materials processing, MHD and plasma simulations, and image processing. While there has been a lot of interest from mathematicians, physicists and engineers in DGM, only scattered information is available and there has been no prior effort in organizing and publishing the existing volume of knowledge on this subject. In May 24-26, 1999 we organized in Newport (Rhode Island, USA), the first international symposium on DGM with equal emphasis on the theory, numerical implementation, and applications. Eighteen invited speakers, lead ers in the field, and thirty-two contributors presented various aspects and addressed open issues on DGM. In this volume we include forty-nine papers presented in the Symposium as well as a survey paper written by the organiz ers. All papers were peer-reviewed. A summary of these papers is included in the survey paper, which also provides a historical perspective of the evolution of DGM and its relation to other numerical methods. We hope this volume will become a major reference in this topic. It is intended for students and researchers who work in theory and application of numerical solution of convection dominated partial differential equations. The papers were written with the assumption that the reader has some knowledge of classical finite elements and finite volume methods.

Download or read book High Order Methods for Computational Physics written by Timothy J. Barth and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of high-order accurate numerical discretization techniques for irregular domains and meshes is often cited as one of the remaining chal lenges facing the field of computational fluid dynamics. In structural me chanics, the advantages of high-order finite element approximation are widely recognized. This is especially true when high-order element approximation is combined with element refinement (h-p refinement). In computational fluid dynamics, high-order discretization methods are infrequently used in the com putation of compressible fluid flow. The hyperbolic nature of the governing equations and the presence of solution discontinuities makes high-order ac curacy difficult to achieve. Consequently, second-order accurate methods are still predominately used in industrial applications even though evidence sug gests that high-order methods may offer a way to significantly improve the resolution and accuracy for these calculations. To address this important topic, a special course was jointly organized by the Applied Vehicle Technology Panel of NATO's Research and Technology Organization (RTO), the von Karman Institute for Fluid Dynamics, and the Numerical Aerospace Simulation Division at the NASA Ames Research Cen ter. The NATO RTO sponsored course entitled "Higher Order Discretization Methods in Computational Fluid Dynamics" was held September 14-18,1998 at the von Karman Institute for Fluid Dynamics in Belgium and September 21-25,1998 at the NASA Ames Research Center in the United States.

Download or read book Mathematical Models and Finite Elements for Reservoir Simulation written by G. Chavent and published by Elsevier. This book was released on 1986-01-01 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulators for oil reservoirs have been developed over the last twenty years and are now widely used by oil companies. The research, however, has taken place largely within the industry itself, and has remained somewhat inaccessible to the scientific community. This book hopes to remedy the situation by means of its synthesized presentation of the models used in reservoir simulation, in a form understandable to both mathematicians and engineers.The book aims to initiate a rigorous mathematical study of the immiscible flow models, partly by using the novel `global pressure' approach in treating incompressible two-phase problems. A finite element approximation technique based on the global pressure variational model is presented, and new approaches to the modelling of various kinds of multiphase flow through porous media are introduced.Much of the material is highly original, and has not been presented elsewhere. The mathematical and numerical models should be of great interest to applied mathematicians, and to engineers seeking an alternative approach to reservoir modelling.

Download or read book Fundamentals of Numerical Reservoir Simulation written by D.W. Peaceman and published by Elsevier. This book was released on 2000-04-01 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of numerical reservoir simulation with high-speed electronic computers has gained wide acceptance throughout the petroleum industry for making engineering studies of a wide variety of oil and gas reservoirs throughout the world. These reservoir simulators have been designed for use by reservoir engineers who possess little or no background in the numerical mathematics upon which they are based. In spite of the efforts to improve numerical methods to make reservoir simulators as reliable, efficient, and automatic as possible, the user of a simulator is faced with a myriad of decisions that have nothing to do with the problem to be solved. This book combines a review of some basic reservoir mechanics with the derivation of the differential equations that reservoir simulators are designed to solve.

Download or read book HI FI Hybridisable Discontinuous Galerkin Method for Incompressible Flows written by Jordi Vila Pérez and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing interest in high-order discretization techniques for CFD applications is motivated by the high accuracy that these methods provide compared to low-order methods. In this project, the hybridizable discontinuous Galerkin (HDG) method is discussed. HDG represents a novel and competitive alternative to the classical discontinuous Galerkin method by substantially reducing the number of coupled unknowns of the discrete problem. Some numerical examples for the simulation of steady incompressible flows are presented, with special emphasis on the HDG stabilization term in order to ensure the optimal convergence of velocity, pressure and gradient of velocity and the superconvergence of a postprocessed velocity field.

Download or read book Efficient High Order Discretizations for Computational Fluid Dynamics written by Martin Kronbichler and published by Springer Nature. This book was released on 2021-01-04 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces modern high-order methods for computational fluid dynamics. As compared to low order finite volumes predominant in today's production codes, higher order discretizations significantly reduce dispersion errors, the main source of error in long-time simulations of flow at higher Reynolds numbers. A major goal of this book is to teach the basics of the discontinuous Galerkin (DG) method in terms of its finite volume and finite element ingredients. It also discusses the computational efficiency of high-order methods versus state-of-the-art low order methods in the finite difference context, given that accuracy requirements in engineering are often not overly strict. The book mainly addresses researchers and doctoral students in engineering, applied mathematics, physics and high-performance computing with a strong interest in the interdisciplinary aspects of computational fluid dynamics. It is also well-suited for practicing computational engineers who would like to gain an overview of discontinuous Galerkin methods, modern algorithmic realizations, and high-performance implementations.

Download or read book An Unfitted Higher order Discontinuous Galerkin Method for Incompressible Two phase Flow with Moving Contact Lines written by Felix Heimann and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Domain Decomposition Methods Algorithms and Theory written by Andrea Toselli and published by Springer Science & Business Media. This book was released on 2006-06-20 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive presentation of some of the most successful and popular domain decomposition preconditioners for finite and spectral element approximations of partial differential equations. It places strong emphasis on both algorithmic and mathematical aspects. It covers in detail important methods such as FETI and balancing Neumann-Neumann methods and algorithms for spectral element methods.

Download or read book A Parallel High order Discontinuous Galerkin Solver for the Unsteady Incompressible Navier Stokes Equations in Complex Geometries written by Khosro Shahbazi and published by . This book was released on 2007 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: We verify the accuracy and stability of the method on several two- and three-dimensional benchmarking problems. On the challenging Orr-Sommerfeld test problem, the equal-order polynomial approximation of the velocity and pressure (Pk - Pk) leads to a stable and accurate solution, while the mixed-order method (Pk - Pk-1) yields a non-physical instability. In simulating vortex shedding past a square cylinder at Re = 100 and in simulating a three-dimensional backward-facing step flow using the equal-order method, excellent agreement with other computational and experimental results are obtained. The developed solver is used to study flow through a two-dimensional bileaflet mechanical heart valve geometry. We conclude that the proposed discontinuous Galerkin method with the Pk - Pk formulation is a suitable scheme for simulations of flows through mechanical heart valve geometries. We develop a parallel method and corresponding code for the numerical solution of the unsteady incompressible Navier-Stokes equations, with application to the direct numerical simulation of transitional and turbulent flows through mechanical heart valves. The solver is based on a simple and efficient scheme, namely a high-order discontinuous Galerkin method on triangular and tetrahedral elements. Spatial discretization of the Stokes operator employed both equal-order (Pk - Pk) and mixed-order (Pk - Pk-1) velocity and pressure approximations. The interior penalty method and local Lax-Friedrichs fluxes are used for the discretizations of the viscous term and the nonlinear term in the divergence form, respectively. A second order approximate algebraic splitting is used to decouple the velocity and pressure calculations leading to an algebraic Helmholtz equation for each component of the velocity and a consistent Poisson equation for the pressure. The consistent Poisson operator is replaced by an equivalent operator, namely that arising from the interior penalty discretization of the standard Poisson operator with appropriate boundary conditions. An explicit lower bound is derived for the penalty parameter of the interior penalty method that ensures the coercivity of the bilinear form. Efficiency aspects of the scheme include knowing an explicit expression for the penalty parameter of the interior penalty method and compact stencil size for the discretizations of the velocity and pressure equations and the nonlinear term.

Download or read book Numerical Simulations of Incompressible Flows written by M. M. Hafez and published by World Scientific. This book was released on 2003 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Consists mainly of papers presented at a workshop ... held in Half Moon Bay, California, June 19-21, 2001 ... to honor Dr. Dochan Kwak on the occasion of his 60th birthday ... organized by M. Hafez of University of California Davis and Dong Ho Lee of Seoul National University"--Dedication, p. ix.

Download or read book Adaptive High order Methods in Computational Fluid Dynamics written by Z. J. Wang and published by World Scientific. This book was released on 2011 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of important contributions by world-renowned experts on adaptive high-order methods in computational fluid dynamics (CFD). It covers several widely used, and still intensively researched methods, including the discontinuous Galerkin, residual distribution, finite volume, differential quadrature, spectral volume, spectral difference, PNPM, and correction procedure via reconstruction methods. The main focus is applications in aerospace engineering, but the book should also be useful in many other engineering disciplines including mechanical, chemical and electrical engineering. Since many of these methods are still evolving, the book will be an excellent reference for researchers and graduate students to gain an understanding of the state of the art and remaining challenges in high-order CFD methods.

Download or read book A high order discontinuous Galerkin method for unsteady compressible flows with immersed boundaries written by Stephan Krämer-Eis and published by Cuvillier Verlag. This book was released on 2017-10-20 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Um die komplexe Physik in kompressiblen Strömungen genauer zu verstehen, kommen vermehrt Simulationen zum Einsatz. Jedoch können weit verbreitete kommerzielle Softwarepakete die Physik aufgrund ihrer niedrigen Genauigkeit oft nicht korrekt erfassen. In dieser Arbeit wird eine diskontinuierliche Galerkin Methode mit hoher Ordnung entwickelt, welche eine hohe Genauigkeit erzielt. Dabei werden insbesondere zwei Probleme, die im Kontext von Verfahren mit hoher Ordnung auftreten, behandelt. Zum einen wird die Gittergenerierung durch das Verwenden einer Immersed Boundary Methode deutlich vereinfacht. Dies bedeutet, dass die Problemgeometrie aus einem deutlich einfacheren Hintergrundgitter herausgeschnitten wird. Die Geometrie wird mit Hilfe einer Level-Set Funktion dargestellt, und die Integration auf den entstehenden geschnittenen Zellen wird mittels einer hierarchischen Moment-Fitting Quadratur durchgeführt. Das Problem der sehr kleinen oder stark gekrümmten Zellen wird durch Zellagglomeration gelöst. Zum zweiten wird die starke Zeitschrittbeschränkung durch anisotrope Gitter mit Hilfe eines lokalen Zeitschrittverfahrens behoben. Diverse numerische Experimente bestätigen die hohe Genauigkeit, Effizienz und geometrische Flexibilität der vorgestellten Methode.