Computational Partial Differential Equations: Numerical Methods and Diffpack Programming

ISBN-13: 9783642628115 / Angielski / Miękka / 2012 / 862 str.

Hans P. Langtangen

Opis

The second edition features lots of improvements and new material. The most significant additions include - finite difference methods and implementations for a 1D time-dependent heat equation (Chapter 1. 7. 6), - a solver for vibration of elastic structures (Chapter 5. 1. 6), - a step-by-step instruction of how to develop and test Diffpack programs for a physical application (Chapters 3. 6 and 3. 13), - construction of non-trivial grids using super elements (Chapters 3. 5. 4, 3. 6. 4, and 3. 13. 4), - additional material on local mesh refinements (Chapter 3. 7), - coupling of Diffpack with other types of software (Appendix B. 3) - high-level programming offinite difference solvers utilizing the new stencil (finite difference operator) concept in Diffpack (Appendix D. 8). Many of the examples, projects, and exercises from the first edition have been revised and improved. Some new exercises and projects have also been added. A hopefully very useful new feature is the compact overview of all the program examples in the book and the associated software files, presented in Chapter 1. 2. Errors have been corrected, many explanations have been extended, and the text has been upgraded to be compatible with Diffpack version 4. 0. The major difficulty when developing programs for numerical solution of partial differential equations is to debug and verify the implementation. This requires an interplay between understanding the mathematical model, the in volved numerics, and the programming tools."

Recenzje

From the reviews of the second edition:

"The aim of this book, as stated in the preface is 'To Teach Numerics along with Diffpack'. ... I feel that the author has been successful with the stated aim, and the content is well directed to the target audience ... . This book will be very useful ... for graduate students or researchers, who intend working with DIFFPACK. It provides an excellent advanced tutorial and users manual for DIFFPACK, while also providing a wealth of first hand computational experience presented by an excellent computational scientist." (Stephen Roberts, gazette The Australian Mathematical Society, Vol. 32 (5), 2005)

"The present book can be considered to be a sort of handbook for Diffpack, yet it is more than just that. ... No one planning to use Diffpack is likely not to benefit from this presentation." (H. Muthsam, Monatshefte für Mathematik, Vol. 143 (4), 2004)

"The present version improves and corrects the text, adds new material, and updates the book to match the version 4.0 of the C++ software package Diffpack. ... this is a very useful book for the users of Diffpack. However, this book deserves a wider readership than the users of Diffpack, because it provides valuable insights of object oriented numerics and state-of-the-art program development using standard tools for numerical programming, data visualization, and scripting techniques based on Perl." (Matti Vuorinen, Zentralblatt MATH, Vol. 1037 (12), 2004)

"This large monograph ... is devoted to an updated presentation of the most important numerical techniques for solving partial differential equations using the software Diffpack Programming. ... Many figures and tables make explanation much more easier, in addition a collection of examples are discussed with many details. ... In addition a complete bibliography and full index is added. In conclusion this book will be certainly very helpful to everybody involving in numerical simulations and having Diffpack software." (Stéphane Métens, Physicalia, Vol. 26 (1), 2004)

"This is the second edition of a popular tutorial on the numerical solution of partial differential equations (PDEs). ... has over 150 exercises and a comparable number of worked-out examples together with computational code. There is an extensive bibliography of 156 references for further reading. ... it should be of interest and use to researchers and practitioners working in computational mechanics and to students aspiring to enter that field. It should make a good text for graduate-level numeric courses. Purchase by libraries is recommended." (RL Huston, Applied Mechanics Reviews, Vol. 56 (6), 2003)

Spis treści

1 Getting Started.- 1.1 The First Diffpack Encounter.- 1.1.1 What is Diffpack?.- 1.1.2 A Simple C++ Program.- 1.1.3 A Simple Diffpack Program.- 1.2 Overview of Application Examples.- 1.2.1 Very Simple Introductory Program Examples.- 1.2.2 Finite Difference Simulators.- 1.2.3 Finite Element Simulators.- 1.2.4 More Advanced Applications.- 1.3 Steady One-Dimensional Heat Conduction.- 1.3.1 The Physical and Mathematical Model.- 1.3.2 A Finite Difference Method.- 1.3.3 Implementation in Diffpack.- 1.3.4 Dissection of the Program.- 1.3.5 Tridiagonal Matrices.- 1.3.6 Variable Coefficients.- 1.3.7 A Nonlinear Heat Conduction Problem.- 1.4 Simulation of Waves.- 1.41 Modeling Vibrations of a String.- 1.4.2 A Finite Difference Method.- 1.4.3 Implementation.- 1.4.4 Visualizing the Results.- 1.4.5 Automating Simulation and Visualization in Scripts.- 1.4.6 A 2D Wave Equation with Variable Wave Velocity.- 1.4.7 A Model for Water Waves.- 1.5 Projects.- 1.5.1 A Uni-Directional Wave Equation.- 1.5.2 Centered Differences for a Boundary-Layer Problem.- 1.5.3 Upwind Differences for a Boundary-Layer Problem.- 1.6 About Programming with Objects.- 1.6.1 Motivation for the Object Concept.- 1.6.2 Example: Implementation of a Vector Class in C++.- 1.6.3 Arrays in Diffpack.- 1.6.4 Example: Design of an ODE Solver Environment.- 1.6.5 Abstractions for Grids and Fields.- 1.7 Coding the PDE Simulator as a Class.- 1.7.1 Steady ID Heat Conduction Revisited.- 1.7.2 Nonlinear ID Heat Conduction Revisited.- 1.7.3 Empirical Investigation of a Numerical Method.- 1.7.4 Simulation of 1D Waves Revisited.- 1.7.5 Simulation of 2D Waves Revisited.- 1.7.6 Transient Heat Conduction.- 1.8 Projects.- 1.8.1 Transient Flow Between Moving Plates.- 1.8.2 Transient Channel Flow.- 1.8.3 Coupled Heat and Fluid Flow.- 1.8.4 Difference Schemes for Transport Equations.- 1.8.5 3D Sound Waves.- 2 Introduction to Finite Element Discretization.- 2.1 Weighted Residual Methods.- 2.1.1 Basic Principles.- 2.1.2 Example: A ID Poisson Equation.- 2.1.3 Treatment of Boundary Conditions.- 2.2 Time Dependent Problems.- 2.2.1 A Wave Equation.- 2.2.2 A Heat Equation.- 2.3 Finite Elements in One Space Dimension.- 2.3.1 Piecewise Polynomials.- 2.3.2 Handling of Essential Boundary Conditions.- 2.3.3 Direct Computation of the Linear System.- 2.3.4 Element-by-Element Formulation.- 2.3.5 Extending the Concepts to Quadratic Elements.- 2.3.6 Summary of the Element-by-Element Algorithm.- 2.4 Example: A ID Wave Equation.- 2.4.1 The Finite Element Equations.- 2.4.2 Interpretation of the Discrete Equations.- 2.4.3 Accuracy and Stability.- 2.5 Naive Implementation.- 2.6 Projects.- 2.6.1 Steady Heat Conduction with Cooling Law.- 2.6.2 Stationary Pipe Flow.- 2.6.3 Transient Pipe Flow.- 2.6.4 Retardation of a Well-Bore.- 2.7 Higher-Dimensional Finite Elements.- 2.7.1 The Bilinear Element and Generalizations.- 2.7.2 The Linear Triangle.- 2.7.3 Example: A 2D Wave Equation.- 2.7.4 Other Two-Dimensional Element Types.- 2.7.5 Three-Dimensional Elements.- 2.8 Calculation of Derivatives.- 2.8.1 Global Least-Squares Smoothing.- 2.8.2 Flux Computations in Heterogeneous Media.- 2.9 Convection-Diffusion Equations.- 2.9.1 A One-Dimensional Model Problem.- 2.9.2 Multi-Dimensional Equations.- 2.9.3 Time-Dependent Problems.- 2.10 Analysis of the Finite Element Method.- 2.10.1 Weak Formulations.- 2.10.2 Variational Problems.- 2.10.3 Results for Continuous Problems.- 2.10.4 Results for Discrete Problems.- 2.10.5 A Priori Error Estimates.- 2.10.6 Numerical Experiments.- 2.10.7 Adaptive Finite Element Methods.- 3 Programming of Finite Element Solvers.- 3.1 A Simple Program for the Poisson Equation.- 3.1.1 Discretization.- 3.1.2 Basic Parts of a Simulator Class.- 3.2 Increasing the Flexibility.- 3.2.1 A Generalized Model Problem.- 3.2.2 Using the Menu System.- 3.2.3 Creating the Grid Object.- 3.3 Some Visualization Tools.- 3.3.1 Storing Fields for Later Visualization.- 3.3.2 Filtering Simres Data.- 3.3.3 Visualizing Diffpack Data in Plotmtv.- 3.3.4 Visualizing Diffpack Data in Gnuplot.- 3.3.5 Visualizing Diffpack Data in Matlab.- 3.3.6 Visualizing Diffpack Data in Vtk.- 3.3.7 Visualizing Diffpack Data in IRIS Explorer.- 3.3.8 Plotting Fields along Lines.- 3.4 Some Useful Diffpack Features.- 3.4.1 The Menu System.- 3.4.2 Multiple Loops.- 3.4.3 Computing Numerical Errors.- 3.4.4 Functors.- 3.4.5 Computing Derivatives of Finite Element Fields.- 3.4.6 Specializing Code in Subclass Solvers.- 3.5 Introducing More Flexibility.- 3.5.1 Setting Boundary Condition Information in the Grid.- 3.5.2 Line and Surface Integrals.- 3.5.3 Simple Mesh Generation Tools.- 3.5.4 Grid Generation by Super Elements.- 3.5.5 Debugging.- 3.5.6 Automatic Report Generation.- 3.5.7 Specializing Code in Subclass Solvers.- 3.5.8 Overriding Menu Answers in the Program.- 3.5.9 Estimating Convergence Rates.- 3.5.10 Axisymmetric Formulations and Cartesian 2D Code.- 3.5.11 Summary.- 3.6 Step-by-Step Development of a Diffpack Solver.- 3.6.1 Physical and Mathematical Problem.- 3.6.2 Editing and Writing Source Code.- 3.6.3 A Simplified Test Case.- 3.6.4 Creating the Grid.- 3.6.5 Running Some Initial 2D Simulations.- 3.6.6 Running Real Simulations.- 3.7 Adaptive Grids.- 3.7.1 Grid Classes with Local Mesh Refinements.- 3.7.2 How to Extend an Existing Simulator.- 3.7.3 Organization of Refinement Criteria.- 3.7.4 Grid Refinements as a Preprocessor.- 3.7.5 Example: Corner-Flow Singularity.- 3.7.6 User-Defined Refinement Criteria.- 3.7.7 Transient Problems.- 3.8 Projects.- 3.8.1 Flow in an Open Inclined Channel.- 3.8.2 Stress Concentration due to Geometric Imperfections.- 3.8.3 A Poisson Problem with Pure Neumann Conditions.- 3.8.4 Lifting Airfoil.- 3.9 A Convection-Diffusion Solver.- 3.10 A Heat Equation Solver.- 3.10.1 Discretization.- 3.10.2 Implementation.- 3.11 A More Flexible Heat Equation Solver.- 3.11.1 About the Model Problem and the Simulator.- 3.11.2 Variable Time Step Size.- 3.11.3 Applying a Transient Solver to a Stationary PDE.- 3.11.4 Thermal Conditions During Welding.- 3.12 Visualization of Time-Dependent Fields.- 3.12.1 Filtering Time-Dependent Simres Data.- 3.12.2 Storing Fields at Selected Time Points.- 3.12.3 Time Series at Selected Spatial Points.- 3.12.4 Using Image Magick Tools.- 3.12.5 Animation Using Plotmtv.- 3.12.6 Animation Using Vtk.- 3.12.7 Animation Using Matlab.- 3.12.8 Real-Time Visualization.- 3.12.9 Handling Simulation and Visualization from a Script.- 3.12.10 Heat Transfer Exercises.- 3.13 A Transient Heat Transfer Application.- 3.13.1 The Mathematical and Physical Model.- 3.13.2 Implementation.- 3.13.3 Testing and Debugging the Initial State.- 3.13.4 Creating the Grid.- 3.13.5 Running Time-Dependent Simulations.- 3.13.6 A Scripting Interface for Automating Simulations.- 3.14 Projects.- 3.14.1 Transient Heat Transfer in a Two-Material Structure.- 3.14.2 Transient Flow with Non-Circular Cross Section.- 3.14.3 Transient Groundwater Flow.- 3.15 Efficient Solution of the Wave Equation.- 3.15.1 Discretization.- 3.15.2 Implementation.- 3.15.3 Extensions of the Model Problem.- 3.15.4 Flexible Representation of Variable Coefficients.- 4 Nonlinear Problems.- 4.1 Discretization and Solution of Nonlinear PDEs.- 4.1.1 Finite Difference Discretization.- 4.1.2 Finite Element Discretization.- 4.1.3 The Group Finite Element Method.- 4.1.4 Successive Substitutions.- 4.1.5 Newton-Raphson’s Method.- 4.1.6 A Transient Nonlinear Heat Conduction Problem.- 4.1.7 Iteration Methods at the PDE Level.- 4.1.8 Continuation Methods.- 4.2 Software Tools for Nonlinear Finite Element Problems.- 4.2.1 A Solver for a Nonlinear Heat Equation.- 4.2.2 Extending the Solver.- 4.3 Projects.- 4.3.1 Operator Splitting for a Reaction-Diffusion Model.- 4.3.2 Compressible Potential Flow.- 5 Solid Mechanics Applications.- 5.1 Linear Thermo-Elasticity.- 5.1.1 The Physical and Mathematical Model.- 5.1.2 A Finite Element Method.- 5.1.3 Engineering Finite Element Notation.- 5.1.4 Implementation.- 5.1.5 Examples.- 5.1.6 Elastic Vibrations.- 5.2 Elasto-Viscoplasticity.- 5.2.1 Basic Physical Features of Elasto-Viscoplasticity.- 5.2.2 A Three-Dimensional Elasto-Viscoplastic Model.- 5.2.3 Simplification; a Forward Scheme in Time.- 5.2.4 Numerical Handling of Yield Criteria.- 5.2.5 Implementation.- 5.2.6 Examples.- 6 Fluid Mechanics Applications.- 6.1 Convection-Diffusion Equations.- 6.1.1 The Physical and Mathematical Model.- 6.1.2 A Finite Element Method.- 6.1.3 Incorporation of Nonlinearities.- 6.1.4 Software Tools.- 6.1.5 Melting and Solidification.- 6.2 Shallow Water Equations.- 6.2.1 The Physical and Mathematical Model.- 6.2.2 Finite Difference Methods on Staggered Grids.- 6.2.3 Implementation.- 6.2.4 Nonlinear and Dispersive Terms.- 6.2.5 Finite Element Methods.- 6.3 An Implicit Finite Element Navier-Stokes Solver.- 6.3.1 The Physical and Mathematical Model.- 6.3.2 A Finite Element Method.- 6.3.3 Solution of the Nonlinear Systems.- 6.3.4 Implementation.- 6.4 A Classical Finite Difference Navier-Stokes Solver.- 6.4.1 Operator Splitting.- 6.4.2 Finite Differences on 3D Staggered Grids.- 6.4.3 A Multigrid Solver for the Pressure Equation.- 6.4.4 Implementation.- 6.5 A Fast Finite Element Navier-Stokes Solver.- 6.5.1 Operator Splitting and Finite Element Discretization.- 6.5.2 An Optimized Implementation.- 6.6 Projects.- 6.6.1 Analysis of Discrete Shallow Water Waves.- 6.6.2 Approximating the Navier-Stokes Equations by a Laplace Equation.- 7 Coupled Problems.- 7.1 Fluid-Structure Interaction; Squeeze-Film Damping.- 7.1.1 The Physical and Mathematical Model.- 7.1.2 Numerical Methods.- 7.1.3 Implementation.- 7.2 Fluid Flow and Heat Conduction in Pipes.- 7.2.1 The Physical and Mathematical Model.- 7.2.2 Numerical Methods.- 7.2.3 Implementation.- 7.3 Projects.- 7.3.1 Transient Spherical-Symmetric Thermo-Elasticity.- 7.3.2 Transient 2D/3D Thermo-Elasticity.- 7.3.3 Convective-Diffusive Transport in Viscous Flow.- 7.3.4 Chemically Reacting Fluid.- B.7 Optimizing Diffpack Codes.- B.7.1 Avoiding Repeated Matrix Factorizations.- B.7.2 Avoiding Repeated Assembly of Linear Systems.- B.7.3 Optimizing the Assembly Process.- B.7.4 Optimizing Array Indexing.- A Mathematical Topics.- A.1 Scaling and Dimensionless Variables.- A.2 Indicial Notation.- A.3 Compact Notation for Difference Equations.- A.4 Stability and Accuracy of Difference Approximations.- A.4.1 Typical Solutions of Simple Prototype PDEs.- A.4.2 Physical Significance of Parameters in the Solution.- A.4.3 Analytical Dispersion Relations.- A.4.4 Solution of Discrete Equations.- A.4.5 Numerical Dispersion Relations.- A.4.6 Convergence.- A.4.7 Stability.- A.4.8 Accuracy.- A.4.9 Truncation Error.- A.4.10 Traditional von Neumann Stability Analysis.- A.4.11 Examples: Analysis of the Heat Equation.- A.5 Exploring the Nature of Some PDEs.- A.5.1 A Hyperbolic Equation.- A.5.2 An Elliptic Equation.- A.5.3 A Parabolic Equation.- A.5.4 The Laplace Equation Solved by a Wave Simulator.- A.5.5 Well-Posed Problems.- B Diffpack Topics.- B.1 Brief Overview of Important Diffpack Classes.- B.2 Diffpack-Related Operating System Interaction.- B.2.1 Unix.- B.2.2 Windows.- B.3 Combining Diffpack with Other Types of Software.- B.3.1 Calling Other Software Packages from Diffpack.- B.3.2 Calling Diffpack from Other Types of Software.- B.4. Basic Diffpack Features.- B.4.1 Diffpack Man Pages.- B.4.2 Standard Command-Line Options.- B.4.3 Generalized Input and Output.- B.4.4 Automatic Verification of a Code.- B.5 Visualization Support.- B.5.1 Curves.- B.5.2 Scalar and Vector Fields.- B.6 Details on Finite Element Programming.- B.6.1 Basic Functions for Finite Element Assembly.- B.6.2 Using Functors for the Integrands.- B.6.3 Integrating Quantities over the Grid or the Boundary.- B.6.4 Class Relations in the Finite Element Engine.- C Iterative Methods for Sparse Linear Systems.- C.1 Classical Iterative Methods.- C.1.1 A General Framework.- C.1.2 Jacobi, Gauss-Seidel, SOR, and SSOR Iteration.- C.2 Conjugate Gradient-Like Iterative Methods.- C.2.1 Galerkin and Least-Squares Methods.- C.2.2 Summary of the Algorithms.- C.2.3 A Framework Based on the Error.- C.3 Preconditioning.- C.3.1 Motivation and Basic Principles.- C.3.2 Classical Iterative Methods as Preconditioners.- C.3.3 Incomplete Factorization Preconditioners.- C.4 Multigrid and Domain Decomposition Methods.- C.4.1 Domain Decomposit ion.- C.4.2 Multigrid Methods.- D Software Tools for Solving Linear Systems.- D.1 Storing and Initializing Linear Systems.- D.1.1 Vector and Matrix Formats.- D.1.2 Detailed Matrix Examples.- D.1.3 Representation of Linear Systems.- D.2 Programming with Linear Solvers.- D.2.1 Gaussian Elimination.- D.2.2 A Simple Demo Program.- D.2.3 A 3D Poisson Equation Solver.- D.3 Classical Iterative Methods.- D.4 Conjugate Gradient-like Methods.- D.4.1 Symmetric Systems.- D.4.2 Nonsymmetric Systems.- D.5 Preconditioning Strategies.- D.6 Convergence History and Stopping Criteria.- D.7 Example: Implicit Methods for Transient Diffusion.- D.8 High-Level Stencil Programming of Finite Difference Schemes.- D.8.1 Finite Difference Stencils.- D.8.2 Basic Structure of a Stencil-Based Simulator.- D.8.3 Defining the Stencils.

O autorze

Prof. H. Petter Langtangen is the director of Center for Biomedical Computing, a Norwegian Center of Excellence at Simula Research Laboratory, and a professor of computer science at the University of Oslo. His research concerns numerical methods and software tools for continuum mechanical problems. Langtangen has been an active developer of open source and commercial software systems for computational sciences. He is a member of the European Academy of Sciences and serves on the editorial board of five leading international journals.