Contents

General remarks and classification of fluid mechanics problems ... 2.6 Characteristic-based methods. 2.7 ... Numerical approximations and the CBS algorithm ... Steady-state field problems - heat conduction, electric and magnetic potential,. 8.
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Contents

Preface to Volume 3 1

2

3

...

Xlll

1

Introduction and the equations of fluid dynamics 1.1 General remarks and classification of fluid mechanics problems discussed in this book 1.2 The governing equations of fluid dynamics 1.3 Incompressible (or nearly incompressible) flows 1.4 Concluding remarks References

1 4 10 12 12

Convection dominated problems - finite element approximations to the convection-diffusion equation 2.1 Introduction 2.2 The steady-state problem in one dimension 2.3 The steady-state problem in two (or three) dimensions 2.4 Steady state - concluding remarks 2.5 Transients - introductory remarks 2.6 Characteristic-based methods 2.7 Taylor-Galerkin procedures for scalar variables 2.8 Steady-state condition 2.9 Non-linear waves and shocks 2.10 Vector-valued variables 2.11 Summary and concluding remarks References

13 13 15 26 30 32 35 47 48 48 52 59 59

A general algorithm for compressible and incompressible flows - the characteristic-based split (CBS) algorithm 3.1 Introduction 3.2 Characteristic-based split (CBS) algorithm 3.3 Explicit, semi-implicit and nearly implicit forms 3.4 ‘Circumventing’ the BabuSka-Brezzi (BB) restrictions 3.5 A single-step version 3.6 Boundary conditions

64 64 67 76 78 80 81

viii Contents

3.7 3.8

The performance of two- and single-step algorithms on an inviscid problem Concluding remarks References

85 87 87

4

Incompressible laminar flow - newtonian and non-newtonian fluids 91 4.1 Introduction and the basic equations 91 4.2 Inviscid, incompressible flow (potential flow) 93 4.3 Use of the CBS algorithm for incompressible or nearly incompressible flows 97 4.4 Boundary-exit conditions i00 4.5 Adaptive mesh refinement 102 4.6 Adaptive mesh generation for transient problems 113 4.7 Importance of stabilizing convective terms 113 4.8 Slow flows - mixed and penalty formulations 113 4.9 Non-newtonian flows - metal and polymer forming 118 4.10 Direct displacement approach to transient metal forming 132 4.1 1 Concluding remarks 133 References 134

5

Free 5.1 5.2 5.3 5.4

surfaces, buoyancy and turbulent incompressible flows Introduction Free surface flows Buoyancy driven flows Turbulent flows References

143 143 144 153 161 165

6

Compressible high-speed gas flow 6.1 Introduction 6.2 The governing equations Boundary conditions - subsonic and supersonic flow 6.3 6.4 Numerical approximations and the CBS algorithm Shock capture 6.5 6.6 Some preliminary examples for the Euler equation 6.7 Adaptive refinement and shock capture in Euler problems 6.8 Three-dimensional inviscid examples in steady state 6.9 Transient two and three-dimensional problems 6.10 Viscous problems in two dimensions 6.11 Three-dimensional viscous problems 6.12 Boundary layer-inviscid Euler solution coupling 6.13 Concluding remarks References

169 169 170 171 173 174 176 180 188 195 197 207 209 212 212

7

Shallow-water problems 7.1 Introduction The basis of the shallow-water equations 7.2 7.3 Numerical approximation

218 218 219 223

Contents ix 7.4 7.5 7.6

Examples of application Drying areas Shallow-water transport References

224 236 237 239

8

Waves Introduction and equations 8.1 8.2 Waves in closed domains - finite element models 8.3 Difficulties in modelling surface waves 8.4 Bed friction and other effects 8.5 The short-wave problem 8.6 Waves in unbounded domains (exterior surface wave problems) Unbounded problems 8.7 8.8 Boundary dampers 8.9 Linking to exterior solutions 8.10 Infinite elements 8.11 Mapped periodic infinite elements 8.12 Ellipsoidal type infinite elements of Burnett and Holford 8.13 Wave envelope infinite elements 8.14 Accuracy of infinite elements 8.15 Transient problems 8.16 Three-dimensional effects in surface waves References

242 242 243 245 245 245 250 253 253 255 259 260 26 1 262 264 265 266 270

9

Computer implementation of the CBS algorithm 9.1 Introduction 9.2 The data input module 9.3 Solution module 9.4 Output module 9.5 Possible extensions to CBSflow References

274 274 275 278 289 289 289

Appendix A: Non-conservative form of Navier-Stokes equations

29 1

Appendix B: Discontinuous Galerkin methods in the solution of the convection-diffusion equation

293

Appendix C: Edge-based finite element formulation

298

Appendix D: Multigrid methods

300

Appendix E: Boundary layer-inviscid flow coupling

302

Author index

307

Subject index

315

Volume 1: The basis 1. Some preliminaries: the standard discrete system 2. A direct approach to problems in elasticity 3. Generalization of the finite element concepts. Galerkin-weighted residual and variational approaches 4. Plane stress and plane strain 5. Axisymmetric stress analysis 6. Three-dimensional stress analysis 7. Steady-state field problems - heat conduction, electric and magnetic potential, fluid flow, etc 8. ‘Standard’ and ‘hierarchical’ element shape functions: some general families of Co continuity 9. Mapped elements and numerical integration - ‘infinite’ and ‘singularity’ elements 10. The patch test, reduced integration, and non-conforming elements 1 1. Mixed formulation and constraints - complete field methods 12. Incompressible problems, mixed methods and other procedures of solution 13. Mixed formulation and constraints - incomplete (hybrid) field methods, boundary/Trefftz methods 14. Errors, recovery processes and error estimates 15. Adaptive finite element refinement 16. Point-based approximations; element-free Galerkin - and other meshless methods 17. The time dimension - semi-discretization of field and dynamic problems and analytical solution procedures 18. The time dimension - discrete approximation in time 19. Coupled systems 20. Computer procedures for finite element analysis Appendix A. Matrix algebra Appendix B. Tensor-indicia1 notation in the approximation of elasticity problems Appendix C. Basic equations of displacement analysis Appendix D. Some integration formulae for a triangle Appendix E. Some integration formulae for a tetrahedron Appendix F. Some vector algebra Appendix G. Integration by parts Appendix H. Solutions exact at nodes Appendix I. Matrix diagonalization or lumping

Volume 2: Solid and structural mechanics 1. 2. 3. 4.

5. 6. 7. 8. 9.

10. 1 1. 12. 13.

General problems in solid mechanics and non-linearity Solution of non-linear algebraic equations Inelastic materials Plate bending approximation: thin (Kirchhoff) plates and C , continuity requirements ‘Thick’ Reissner-Mindlin plates - irreducible and mixed formulations Shells as an assembly of flat elements Axisymmetric shells Shells as a special case of three-dimensional analysis - Reissner-Mindlin assumptions Semi-analytical finite element processes - use of orthogonal functions and ‘finite strip’ methods Geometrically non-linear problems - finite deformation Non-linear structural problems - large displacement and instability Pseudo-rigid and rigid-flexible bodies Computer procedures for finite element analysis Appendix A: Invariants of second-order tensors