Computational Fluid Dynamics

Transcription

1 Computational Fluid Dynamics A Practical Approach Jiyuan Tu RMIT University, Australia Guan Heng Yeoh Australian Nuclear Science and Technology Organisation Chaoqun Liu University of Texas, Arlington ^fl f ^ ^ M.Jgyjyffe^ ELSEVIER. AMSTERDAM BOSTON. HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Butterworth-Heinemann is an imprint of Elsevier

2 r Contents Preface Acknowledgments XI XV 1 Introduction 1.1 What is computational fluid dynamics Advantages of computational fluid dynamics Application of computational fluid dynamics As a research tool As an education tool to learn basic thermal-fluid science As a design tool Aerospace Automotive engineering Chemical and mineral processing Civil and environmental engineering Power generation Sports The future of computational fluid dynamics Summary CFD Solution Procedure A Beginning 2.1 Introduction 2.2 Problem setup pre-process Creation of geometry step Mesh generation step

3 Contents Selection of physics and fluid properties step Specincation of boundary conditions step Numerical Solution CFD solver Initialization and Solution control step Monitoring convergence step Result report and visualization post-process ^-Yplots Vector plots Contour plots Other plots Data report and Output Animation 2.5 Summary Governing Equations for CFD Fundamentals Introduction 3.2 The continuity equation Mass conservation Physical Interpretation Comments 3.3 The momentum equation Force balance Physical interpretation Comments 3.4 The energy equation Energy conservation Physical interpretation Comments 3.5 The additional equations for turbulent flow What is turbulence k-e Two-equation turbulence model Comments

4 Contents vii 3.6 Generic form of the governing equations for CFD 3.7 Physical boundary conditions of the governing equations 3.8 Summary CFD Techniques The Basics 4.1 Introduction 4.2 Discretization of governing equations Finite-difference method Finite-volume method Converting governing equations to algebraic equation System 4.3 Numerical Solutions to algebraic equations Direct methods Iterative methods Pressure-velocity coupling SIMPLE scheme 4.4 Summary CFD Solution Analysis Essentials 5.1 Introduction 5.2 Consistency 5.3 Stability 5.4 Convergence What is convergence Residuais and convergence tolerance Convergence difficulty and using under-relaxation Accelerating convergence 5.5 Accuracy Source of Solution errors Controlling the Solution errors Verification and Validation

5 6 5.6 Efficiency 5.7 Case studies Test case A: Channel flow Test case B: flow over a 90 bend 5.8 Summary Practical Guidelines for CFD Simulation and Analysis Introduction Guidelines on grid generation Overview of grid generation Guidelines on grid quality and grid design Local refinement and Solution adaptation Guidelines on boundary conditions Overview of setting boundary conditions Guidelines on inlet boundary conditions Guidelines on outlet boundary conditions Guidelines on wall boundary conditions Guidelines on symmetry and periodic boundary conditions Guidelines on turbulence modeling Overview of turbulence modeling approaches Strategy for selecting turbulence modeis Near-wall treatments Setting boundary conditions Test case: assessment of two-equation turbulence modeling for hydrofoil flows Summary Some Applications of CFD with Examples Introduction 7.2 To assist in design process as a design tool

6 Contents ix Indoor airflow distribution To enhance understanding as a research tool Other important applications Heat transfer coupled with fluid flow A buoyant free-standing Are Flow over vehicle platoon Air/Particle flow in the human nasal cavity High-speed flows Summary Some Advanced Topics in CFD Introduction Advances in numerical methods and techniques Incompressible flows Compressible flows Moving grids Multigrid methods Parallel Computing Immersed boundary methods Advances in computational modeis Direct numerical Simulation (DNS) Large eddy Simulation (LES) RANS-LES coupling for turbulent flows Multiphase flows Combustion Fluid-structure interaction Physiological fluid dynamics Other numerical approaches for computation of fluid dynamics Lattice Boltzmann method Monte Carlo method Particle methods 404

7 x Contents 8.5 Summary A. Füll Derivation of Conservation Equations Upwind Schemes 414 U- Explicit and Implicit Methods 416 D Learning Program 418 EJ CFD Assignments and Guideline for CFD Project 421 References 437 Further Suggested Reading 453 Index 455