Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- 1 Introduction and Background
- 2 Mathematical Models of Fluid Flow
- 3 Numerical Methods for the Solution of Partial Differential Equations
- 4 Fundamental Stability Theory
- 5 Shock Capturing Schemes I: Scalar Conservation Laws
- 6 Shock Capturing Schemes II: Systems of Equations and Gas Dynamics
- 7 Discretization Schemes for Flows in Complex Multi-dimensional Domains
- 8 The Calculation of Viscous flow
- 9 Overview of Time Integration Methods
- 10 Steady State Problems
- 11 Time-Accurate Methods for Unsteady Flow
- 12 Energy Stability for Nonlinear Problems
- 13 High order Methods for Structured Meshes
- 14 High Order Methods for Unstructured Meshes
- 15 Aerodynamic Shape Optimization
- Appendix A Vector and Function Spaces
- Appendix B Approximation Theory
- Appendix C Polynomial Interpolation, Differentiation, and Integration
- Appendix D Potential Flow Methods
- Appendix E Fundamental Stability Theory II
- Appendix F Turbulence Models
- References
- Index
- Plates
11 - Time-Accurate Methods for Unsteady Flow
Published online by Cambridge University Press: 12 August 2022
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- 1 Introduction and Background
- 2 Mathematical Models of Fluid Flow
- 3 Numerical Methods for the Solution of Partial Differential Equations
- 4 Fundamental Stability Theory
- 5 Shock Capturing Schemes I: Scalar Conservation Laws
- 6 Shock Capturing Schemes II: Systems of Equations and Gas Dynamics
- 7 Discretization Schemes for Flows in Complex Multi-dimensional Domains
- 8 The Calculation of Viscous flow
- 9 Overview of Time Integration Methods
- 10 Steady State Problems
- 11 Time-Accurate Methods for Unsteady Flow
- 12 Energy Stability for Nonlinear Problems
- 13 High order Methods for Structured Meshes
- 14 High Order Methods for Unstructured Meshes
- 15 Aerodynamic Shape Optimization
- Appendix A Vector and Function Spaces
- Appendix B Approximation Theory
- Appendix C Polynomial Interpolation, Differentiation, and Integration
- Appendix D Potential Flow Methods
- Appendix E Fundamental Stability Theory II
- Appendix F Turbulence Models
- References
- Index
- Plates
Summary
This chapter addresses issues arising in the time accurate simulation of unsteady flows. In order to enable accurate simulations of time dependent flows with moving shocks and contact discontinuities, there is a need for higher order accurate time discretization schemes that can preserve the TVD property. Additionally, time dependent calculations are needed for a number of important applications, such as flutter analysis or the analysis of the flow past a helicopter rotor, in which the stability limit of an explicit scheme forces the use of much smaller time steps than would be needed for an accurate simulation. This motivates the “dual time stepping” scheme, in which a multigrid explicit scheme can be used in an inner iteration to solve the equations of a fully implicit time stepping scheme. Such schemes are developed in this chapter.
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- Computational Aerodynamics , pp. 367 - 386Publisher: Cambridge University PressPrint publication year: 2022