To classify a book as 'experimental' rather than 'theoretical' or as 'pure' rather than 'applied' is liable to imply umeal distinctions. Nevertheless, some Classification is necessary to teIl the potential reader whether the book is for him. In this spirit, this book may be said to treat fluid dynamies as a branch of physics, rather than as a branch of applied mathematics or of engineering. I have often heard expressions of the need for such a book, and certainly I have feIt it in my own teaching. I have written it primariIy for students of physics and of physics-based applied science, aIthough I hope others may find it useful. The book differs from existing 'fundamental' books in placing much greater emphasis on what we know through laboratory experiments and their physical interpretation and less on the mathe­ matieal formalism. It differs from existing 'applied' books in that the choice of topics has been made for the insight they give into the behaviour of fluids in motion rather than for their practical importance. There are differences also from many existing books on fluid dynamics in the branches treated, reflecting to some extent shifts of interest in reeent years. In particular, geophysical and astrophysical applications have prompted important fundamental developments in topics such as conveetion, stratified flow, and the dynamics of rotating fluids. These developments have hitherto been reflected in the contents of textbooks only to a limited extent.

Table of Contents:
1. Introduction.- 1.1 Preamble.- 1.2 Scope of book.- 1.3 Notation and definitions.- 2. Pipe and Channel Flow.- 2.1 Introduction.- 2.2 Laminar flow theory: channel.- 2.3 Laminar flow theory: pipe.- 2.4 The Reynolds number.- 2.5 The entry length.- 2.6 Transition to turbulent flow.- 2.7 Relationship between flow rate and pressure gradient.- 3. Flow Past a Circular Cylinder.- 3.1 Introduction.- 3.2 The Reynolds number.- 3.3 Flow patterns.- 3.4 Drag.- 4. Convection in Horizontal Layers.- 4.1 The configuration.- 4.2 Onset of motion.- 4.3 Flow regimes.- 5. Equations of Motion.- 5.1 Introduction.- 5.2 Fluid particles and continuum mechanics.- 5.3 Eulerian and Langrangian co-ordinates.- 5.4 Continuity equation.- 5.5 The substantive derivative.- 5.6 The Navier—Stokes equation.- 5.7 Boundary conditions.- 5.8 Condition for incompressibility.- Appendix: Derivation of viscous term of dynamical equation.- 6. Further Basic Ideas.- 6.1 Streamlines, streamtubes, particle paths and streaklines.- 6.2 Computations for flow past a circular cylinder.- 6.3 The stream function.- 6.4 Vorticity.- 6.5 Vorticity equation.- 6.6 Circulation.- 7. Dynamical Similarity.- 7.1 Introduction.- 7.2 Condition for dynamical similarity: Reynolds number.- 7.3 Dependent quantities.- 7.4 Other governing non-dimensional parameters.- 8. Low and High Reynolds Numbers.- 8.1 Physical significance of the Reynolds number.- 8.2 Low Reynolds number.- 8.3 High Reynolds number.- 9. Some Solutions of the Viscous Flow Equations.- 9.1 Introduction.- 9.2 Poiseuille flow.- 9.3 Rotating Couette flow.- 9.4 Stokes flow past a sphere.- 9.5 Low Reynolds number flow past a cylinder.- 10. Inviscid Flow.- 10.1 Introduction.- 10.2 Kelvin circulation theorem.- 10.3 Irrotational motion.- 10.4 Bernoulli’s equation.- 10.5 Drag in inviscidflow: d’Alembert’s ‘paradox’.- 10.6 Applications of Bernoulli’s equation.- 10.7 Some definitions.- 11. Boundary Layers and Related Topics.- 11.1 Boundary layer formation.- 11.2 The boundary layer approximation.- 11.3 Zero pressure gradient solution.- 11.4 Boundary layer separation.- 11.5 Drag on bluff bodies.- 11.6 Streamlining.- 11.7 Wakes.- 11.8 Jets.- 11.9 Momentum and energy in viscous flow.- 12. Lift.- 12.1 Introduction.- 12.2 Two-dimensional aerofoils.- 12.3 Three-dimensional aerofoils.- 12.4 Spinning bodies.- 13. Thermal Flows: Basic Equations and Concepts.- 13.1 Introduction.- 13.2 Equations of convection.- 13.3 Classification of convective flows.- 13.4 Forced convection.- 13.5 Flow with concentration variations (mass transfer).- 14. Free Convection.- 14.1 Introduction.- 14.2 The governing non-dimensional parameters.- 14.3 The adiabatic temperature gradient.- 14.4 Free convection as a heat engine.- 14.5 Convection from a heated vertical surface.- 14.6 Thermal plumes.- 14.7 Convection in fluid layers.- Appendix: The Boussinesq approximation in free convection.- 15. Flow in Rotating Fluids.- 15.1 Introduction.- 15.2 Centrifugal and Coriolis forces.- 15.3 Geostrophic flow and the Taylor—Proud man theorem.- 15.4 Taylor columns.- 15.5 Ekman layers.- 15.6 Intrinsic stability and inertial waves.- 15.7 Rossby waves.- 15.8 Convection in a rotating annulus.- 16. Stratified Flow.- 16.1 Basic concepts.- 16.2 Blocking.- 16.3 Lee waves.- 16.4 Internal waves.- 16.5 Stratification and rotation.- 17. Instability Phenomena.- 17.1 Introduction.- 17.2 Surface tension instability of a liquid column.- 17.3 Convection due to internal heat generation.- 17.4 Convection due to surface tension variations.- 17.5 Instability of rotating Couette flow.- 17.6 Shear flowinstability.- 18. The Theory of Hydro Dynamic Stability.- 18.1 The nature of linear stability theory.- 18.2 Onset of Bénard convection.- 18.3 Overstability.- 18.4 Rotating Couette flow.- 18.5 Boundary layer stability.- 19. Transition to Turbulence.- 19.1 Boundary layer transition.- 19.2 Transition in jets and other free shear flows.- 19.3 Pipe flow transition.- 20. Turbulence.- 20.1 The nature of turbulent motion.- 20.2 Introduction to the statistical description of turbulent motion.- 20.3 Formulation of the statistical description.- 20.4 Turbulence equations.- 20.5 Calculation methods.- 20.6 Interpretation of correlations.- 20.7 Spectra.- 20.8 The concept of eddies.- 21. Homogeneous Isotropic Turbulence.- 21.1 Introduction.- 21.2 Space correlations and the closure problem.- 21.3 Spectra and the energy cascade.- 21.4 Dynamical processes of the energy cascade.- 22. The Structure of Turbulent Flows.- 22.1 Introduction.- 22.2 Reynolds number similarity and self-preservation.- 22.3 Intermittency and entrainment.- 22.4 The structure of a turbulent wake.- 22.5 Turbulent motion near a wall.- 22.6 Large eddies in a boundary layer.- 22.7 The Coanda effect.- 22.8 Stratified shear flows.- 22.9 Reverse transition.- 23. Experimental Methods.- 23.1 General aspects of experimental fluid dynamics.- 23.2 Velocity measurement.- 23.3 Pressure and temperature measurement.- 23.4 Flow visualization.- 24. Practical Situations.- 24.1 Introduction.- 24.2 Cloud patterns.- 24.3 Waves in the atmospheric circulation.- 24.4 Continental drift and convection in the Earth’s mantle.- 24.5 Solar granulation.- 24.6 Effluent dispersal.- 24.7 Wind effects on structures.- 24.8 Boundary layer control: vortex generators.- 24.9 Fluidics.- 24.10 Undulatory swimming.- 24.11 Convection from the human body.-24.12 The flight of a boomerang.- Notation.- Problems.- Bibliography and References.