Environmental Hydraulics of Open Channel Flows

Transcription

1 Environmental Hydraulics of Open Channel Flows Hubert Chanson ME, ENSHM Grenoble, INSTN, PhD (Cant), DEng (Qld) Eur Ing, MIEAust, MIAHR 13th Arthur Ippen awardee (IAHR) Reader in Environmental Fluid Mechanics and Water Engineering The University of Queensland, Australia Web site: ELSEVIER B H"NEMANN H AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD A PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO

2 Contents Preface Acknowledgements About the author Dedication Glossary List of symbols Part 1 Introduction to Open Channel Flows 1. Introduction 1.1 Presentation 1.2 Fluid properties 1.3 Fluid statics 1.4 Open channel flows 1.5 Exercises 2. Fundamentals of open channel flows 2.1 Presentation 2.2 Fundamental principles 2.3 Open channel hydraulics of short, frictionless transitions 2.4 The hydraulic jump 2.5 Open channel flow in long channels 2.6 Summary 2.6 Exercises IX xvi xviii xxi xxii xlv Part 2 Turbulent Mixing and Dispersion in Rivers and Estuaries: An Introduction Introduction to mixing and dispersion in natural waterways Introduction Laminar and turbulent flows Basic definitions Structure of the section Appendix A - Application: buoyancy force exerted on a submerged air bubble Appendix B - Freshwater properties Exercises Exercise solutions Turbulent shear flows Presentation Jets and wakes 53

3 vi Contents 4.3 Boundary layer flows Fully developed open channel flows Mixing in turbulent shear flows Exercises Exercise solutions Diffusion: basic theory Basic equations Applications Appendix A - Mathematical aids Exercises Exercise solutions Advective diffusion Basic equations Basic applications Two- and three-dimensional applications Exercises Exercise solutions Turbulent dispersion and mixing: 1. Vertical and transverse mixing Introduction Flow resistance in open channel flows Vertical and transverse (lateral) mixing in turbulent river flows Turbulent mixing applications Discussion Appendix A - Friction factor calculations Appendix B - Random walk model Appendix C - Turbulent mixing in hydraulic jumps and bores Exercises Exercise solutions Turbulent dispersion and mixing: 2. Longitudinal dispersion Introduction One-dimensional turbulent dispersion Longitudinal dispersion in natural streams Approximate models for longitudinal dispersion Design applications Exercises Exercise solutions Turbulent dispersion in natural systems Introduction Longitudinal dispersion in natural rivers with dead zones Dispersion and transport of reactive contaminants Transport with reaction Appendix A - Air-water mass transfer in air-water flows Appendix B - Solubility of nitrogen, oxygen and argon in water 138

4 9.7 Appendix C - Molecular diffusion coefficients in water (after Chanson 1997a) Exercises Exercise solutions Mixing in estuaries Presentation Basic mechanisms Applications Turbulent mixing and dispersion coefficients in estuaries Applications Appendix A - Observations of mixing and dispersion coefficients in estuarine zones Exercises Exercise solutions 175 Part 2 Revision exercises 177 Assignment solutions 179 Part 3 Introduction to Unsteady Open Channel Flows Unsteady open channel flows: 1. Basic equations Introduction Basic equations Method of characteristics Discussion Exercises Exercise solutions / Unsteady open channel flows: 2. Applications Introduction Propagation of waves The simple wave problem Positive and negative surges The kinematic wave problem The diffusion wave problem Appendix A - Gaussian error functions Exercises Exercise solutions Unsteady open channel flows: 3. Application to dam break wave Introduction Dam break wave in a horizontal channel Effects of flow resistance Embankment dam failures Related flow situations * Exercises Exercise solutions 300 Contents vii

5 Contents 14. Numerical modelling of unsteady open channel flows Introduction Explicit finite difference methods Implicit finite difference methods Exercises 315 Part 3 Revision exercises 316 Revision exercise no Revision exercise no Revision exercise no Revision exercise no Part 4 Interactions between Flowing Water and its Surroundings Interactions betweenflowingwater and its surroundings: introduction Presentation Terminology Structure of this section Interaction betweenflowingwater and solid boundaries: sediment processes Introduction Physical properties of sediments Threshold of sediment bed motion Sediment transport Total sediment transport rate Exercises Interaction betweenflowingwater and free surfaces: self-aeration and air entrainment Introduction Free-surface aeration in turbulentflows:basic mechanisms Dimensional analysis and similitude Basic metrology in air-water flow studies Applications Appendix A - Air bubble diffusion in plunging j et flows (after Chanson 1997a) Appendix B -Air bubble diffusion in self-aerated supercritical flows Appendix C - Air bubble diffusion in high-velocity water jets Exercises 396 Appendix A: Constants and fluid properties 399 Appendix B: Unit conversions 403 References 406 Abbreviations of journals and institutions 420 Common bibliographical abbreviations 421 Index 423