High-Resolution Methods for Incompressible and Low-Speed Flows


Book Description

The study of incompressible ?ows is vital to many areas of science and te- nology. This includes most of the ?uid dynamics that one ?nds in everyday life from the ?ow of air in a room to most weather phenomena. Inundertakingthesimulationofincompressible?uid?ows,oneoftentakes many issues for granted. As these ?ows become more realistic, the problems encountered become more vexing from a computational point-of-view. These range from the benign to the profound. At once, one must contend with the basic character of incompressible ?ows where sound waves have been analytically removed from the ?ow. As a consequence vortical ?ows have been analytically “preconditioned,” but the ?ow has a certain non-physical character (sound waves of in?nite velocity). At low speeds the ?ow will be deterministic and ordered, i.e., laminar. Laminar ?ows are governed by a balance between the inertial and viscous forces in the ?ow that provides the stability. Flows are often characterized by a dimensionless number known as the Reynolds number, which is the ratio of inertial to viscous forces in a ?ow. Laminar ?ows correspond to smaller Reynolds numbers. Even though laminar ?ows are organized in an orderly manner, the ?ows may exhibit instabilities and bifurcation phenomena which may eventually lead to transition and turbulence. Numerical modelling of suchphenomenarequireshighaccuracyandmostimportantlytogaingreater insight into the relationship of the numerical methods with the ?ow physics.




Solution Techniques for Large-scale CFD Problems


Book Description

Current CFD problems of interest are typically of a large-scalenature, characterized by a size and complexity demanding thecombined efforts of interdisciplinary teams from engineering,mathematics, computer science and physics. This book thus groups aprestigious cross-section of internationally known scientistsinvited to expound on the following themes: * Algorithms for vector, parallel and virtual-parallelarchitectures * Algorithms for massively parallel architectures * Convergence enhancement techniques, namely preconditionedinterative methods for implicit or fully-coupled approaches * Convergence enhancement techniques, such as defect correction,multigrid, formulation preconditioning and zonal methods * Application of these techniques to large-scale CFD analysis anddesign. This book should prove equally valuable for CFD developers,practitioners and graduate students.




Adaptive High-order Methods In Computational Fluid Dynamics


Book Description

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.




Parallel Solution of Partial Differential Equations


Book Description

This IMA Volume in Mathematics and its Applications PARALLEL SOLUTION OF PARTIAL DIFFERENTIAL EQUATIONS is based on the proceedings of a workshop with the same title. The work shop was an integral part of the 1996-97IMA program on "MATHEMAT ICS IN HIGH-PERFORMANCE COMPUTING." I would like to thank Petter Bj0rstad of the Institutt for Informatikk, University of Bergen and Mitchell Luskin of the School of Mathematics, University of Minnesota for their excellent work as organizers of the meeting and for editing the proceedings. I also take this opportunity to thank the National Science Founda tion (NSF), Department of Energy (DOE), and the Army Research Office (ARO), whose financial support made the workshop possible. Willard Miller, Jr., Professor and Director v PREFACE The numerical solution of partial differential equations has been of major importance to the development of many technologies and has been the target of much of the development of parallel computer hardware and software. Parallel computers offer the promise of greatly increased perfor mance and the routine calculation of previously intractable problems. The papers in this volume were presented at the IMA workshop on the Paral lel Solution of PDE held during June 9-13, 1997. The workshop brought together leading numerical analysts, computer scientists, and engineers to assess the state-of-the-art and to consider future directions.




Krylov Solvers for Linear Algebraic Systems


Book Description

The first four chapters of this book give a comprehensive and unified theory of the Krylov methods. Many of these are shown to be particular examples ofthe block conjugate-gradient algorithm and it is this observation thatpermits the unification of the theory. The two major sub-classes of thosemethods, the Lanczos and the Hestenes-Stiefel, are developed in parallel asnatural generalisations of the Orthodir (GCR) and Orthomin algorithms. Theseare themselves based on Arnoldi's algorithm and a generalised Gram-Schmidtalgorithm and their properties, in particular their stability properties,are determined by the two matrices that define the block conjugate-gradientalgorithm. These are the matrix of coefficients and the preconditioningmatrix.In Chapter 5 the"transpose-free" algorithms based on the conjugate-gradient squared algorithm are presented while Chapter 6 examines the various ways in which the QMR technique has been exploited. Look-ahead methods and general block methods are dealt with in Chapters 7 and 8 while Chapter 9 is devoted to error analysis of two basic algorithms.In Chapter 10 the results of numerical testing of the more important algorithms in their basic forms (i.e. without look-ahead or preconditioning) are presented and these are related to the structure of the algorithms and the general theory. Graphs illustrating the performances of various algorithm/problem combinations are given via a CD-ROM.Chapter 11, by far the longest, gives a survey of preconditioning techniques. These range from the old idea of polynomial preconditioning via SOR and ILU preconditioning to methods like SpAI, AInv and the multigrid methods that were developed specifically for use with parallel computers. Chapter 12 is devoted to dual algorithms like Orthores and the reverse algorithms of Hegedus. Finally certain ancillary matters like reduction to Hessenberg form, Chebychev polynomials and the companion matrix are described in a series of appendices.·comprehensive and unified approach·up-to-date chapter on preconditioners·complete theory of stability·includes dual and reverse methods·comparison of algorithms on CD-ROM·objective assessment of algorithms




Computational Fluid Dynamics for the 21st Century


Book Description

This volume contains new trends of computational fluid dynamics for the 21st century and consists of papers especially useful to the younger generation of scientists and engineers in this field. Topics include cartesian, gridless and higher-order schemes, and flow-visualization techniques.




Parallel Computational Fluid Dynamics '95


Book Description

Parallel Computational Fluid Dynamics(CFD) is an internationally recognised fast-growing field. Since 1989, the number of participants attending Parallel CFD Conferences has doubled.In order to keep track of current global developments, the Parallel CFD Conference annually brings scientists together to discuss and report results on the utilization of parallel computing as a practical computational tool for solving complex fluid dynamic problems. This volume contains the results of research conducted during the past year.Subject areas covered include: novel parallel algorithms, parallel Euler and Navier-Stokes solvers, parallel Direct Simulation Monte Carlo method and parallel multigrid techniques. The content of the book also demonstrates that considerable effort is being made to utilize parallel computing to solve a variety of fluid dynamics problems in topics such as climate modeling, consultation, aerodynamics and in many other areas.Readers of this book will gain a valid insight into the exciting recent developments in Parallel CFD research.




Parallel Computational Fluid Dynamics '98


Book Description

This book contains the papers presented at the Parallel Computational Fluid Dynamics 1998 Conference. The book is focused on new developments and applications of parallel technology. Key topics are introduced through contributed papers and invited lectures. These include typical algorithmic developments, such as: distributed computing, domain decomposition and parallel algorithm. Some of the papers address the evaluations of software and machine performance and software tool environments. The application of parallel computers to complex fluid dynamics problems are also conveyed through sessions such as DNS/LES, combustion and reacting flows, industrial applications, water resources and environmental flows.The editors believe this book will provide many researchers, much beyond those contributing to this volume, with fresh information and reference.