Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

MECHANICS OF COASTAL SEDIMENT TRANSPORT

ADVANCED SERIES SERIES ON ONOCEAN OCEANENGINEERING ENGINEERING ADVANCED

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

Series Editor Editor-in-Chief -in-Chief Series Philip LL- F F Liu Liu (Cornell (Cornell University) University) Philip Vol. 11The TheApplied AppliedDynamics DynamicsofofOcean OceanSurface SurfaceWaves Waves Vol. by Chiang Chiang C C Mel Mei (MIT) (MIT) by Vd. 2 2 Water WaterWave Wave Mechanics Mechanics for for Engineers Engineersand andScientists Scientists Vol. by Robert Robert G G Dean Dean (Univ. (Univ. Florida) Florida) and and Robert Robert A A Dalrymple Dalrymple by (Univ. Delaware) Delaware) (Univ. 3 Mechanics MechanicsofofCoastal CoastalSediment SedimentTransport Transport Vol. 3 Vol. by Jergen Jsrgen Fredsee Fredsoe and and Rolf Rolf Deigaard Deigaard (Tech. Univ. Univ. Denmark) Denmark) by CoastalBottom BottomBoundary BoundaryLayers Layersand andSediment SedimentTransport Transport Vd. 4 Coastal Vol. by Peter Peter Nielsen Nielsen (Univ. (Univ. Queensland) Queensland) by Forthcoming titles: titles: Forthcoming Water Waves Propagation Over Over Uneven UnevenBottoms Bottoms Water Waves Propagation by Maarten W W Dingemans Dingemans (Delft Hydraulics) Hydraulics) by Maarten Ooean Outfall Outfall Design Design Ocean by R Wood Wood (Univ. Cantebury) (Univ. Canterbury) by Ian an R Tsunami Run-up Tsunami Run-up by Philip LL- F F Liu Liu (Comell Univ.), Costas Synolakis (Univ. Southern Southem California), California), Costas Synolakis (Cornell Univ.), by Philip Harry Yeh (Univ. Washington) and Nobu Shuto Shuto o (l(Tohoku hoku Univ.) (Univ. Washington) Harry Yeh Physical and Laboratory in Coastal Coastal Engineering Engineering Laboratory Techniques Techniques in Models and Physical Models by Steven A. A. Hughes Hughes (Coastal Engineering Research ResearchCenter, Center, USA) USA) (Coastal Engineering by Steven Kalman Filter Method Analysis of Vibrations Due Water Waves Waves Method in in the the Analysis of Vibrations Due to to Water Kalman Filter by Piotr Wilde Wilde and and Andrzej Andnej Kozakiewicz Kozakiewicz (Inst. (Inst. Hydroengineering, Polish Academy of by Piotr Sciences) Sciences) Numerical Ocean Dynamics Dynamics of Ocean Modelling of Numerical Modelling by Kowalik (Univ. TS S Murty Murty (Inst. BC) (Inst. Ocean Science, BC) and T (Univ. Alaska) Alaska) and by Zygmunt Zygmunt Kowalik Beach Practice Beach Nourishment: Nourishment: Theory Theory and and Practice by G Dean Dean (Univ. Florida) (Univ. Florida) by Robet7 Robert G Design and Construction of Maritime Structures Structures for for Protection Protection Against Against Waves Waves Design and Construction of Maritime by Miguel A Losada (Univ. da Cantabria) and Nobuhisa (Univ. Delaware) (Univ. Delaware) and Kobayashi by Miguel A Losada (Univ. da Cantabria)

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

Advanced Series on Ocean Engineering - Volume 3

MECHANICS OF COASTAL SEDIMENT TRANSPORT

Jorgen Fredsoe Rolf Deigaard Institute of Hydrodynamics and Hydraulic Engineering Technical University of Denmark

`r World Scientific NEW JERSEY • LONDON • SINGAPORE • BEIJING • SHANGHAI • HONG KONG • TAIPEI • CHENNAI

Published by

World Scientific Publishing Co. Pte. Ltd. 5 Toh Tuck Link, Singapore 596224

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

USA office: 27 Warren Street, Suite 401-402, Hackensack, NJ 07601 UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE

Library of Congress Cataloging-in-Publication Data Fredsoe, JOrgen. Mechanics of coastal sediment transport / JOrgen Fredsoe and Rolf Deigaard. p. cm. --(Advanced series on ocean engineering ; v. 3) Includes bibliographical references and index.

ISBN 9810208405 -- ISBN 9810208413 (pbk) 1. Coast changes . 2. Sediment transport. I. Deigaard, Rolf. II. Title. III. Series. GB451.2.F74 1992

551.3'6--dc20

92-38727 CIP

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

First published 1992 Reprinted 1993 (pbk) Reprinted 1994, 2005

Copyright © 1992 by World Scientific Publishing Co. Pte. Ltd. All rights reserved This book, or parts thereof may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the Publisher.

For photocopying of material in this volume, please pay a copying fee through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to photocopy is not required from the publisher.

Printed in Singapore by World Scientific Printers (S) Pte Ltd

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

Contents

INTRODUCTION ...................................................... LIST OF SYMBOLS

ix

................................................... xiii

1. Basic concepts of potential wave theory 1.1 Waves propagating over a horizontal bottom .................. 1 1.2 Wave energy ................................................. 9 1.3 Radiation stresses ........................................... 11 1.4 Irregular waves .............................................. 13 References ....................................................... 16 2. Wave boundary layers 2.1 Introduction ................................................ 17 2.2 The momentum integral method for the turbulent wave boundary layer .................................................... 20 2.3 Detailed modelling of the wave boundary layer .............. 34 2.4 Streaming .................................................. 44 2.5 Energy dissipation in the wave boundary layer ............... 49 References ....................................................... 52

3. Bed friction and turbulence in wave-current motion 3.1 Simple considerations on changes in the shape of the velocity profile and increase in bed shear stress ...................... 3.2 The integrated momentum method applied to combined wavecurrent motion .............................................. 3.3 Refined modelling of the wave-current motion ............... References .......................................................

56 66 77 81

4. Waves in the surf zone 4.1 Wave-breaking ..............................................

83

vi

4.2 Modelling of variation of wave height and water level in the surf zone .................................................... 89 ................................ 112 4.3 Turbulence in the surf zone References ...................................................... 125

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

5. Wave- driven currents 5.1 The longshore current ...................................... 5.2 Further developments of longshore current models .......... 5.3 Wave-driven currents on a non-uniform beach profile ....... 5.4 Low frequency oscillations .................................. References ......................................................

129 137 149 161 166

6. Current velocity distribution in the surf zone 6.1 Normally incident waves, shear stress distribution .......... 171 6.2 Normally incident waves, the undertow ..................... 178 References ...................................................... 192

7. Basic concepts of sediment transport 7.1 Transport modes ........................................... 7.2 Sediment properties ........................................ 7.3 Critical bed shear stress .................................... 7.4 Bed load transportation .................................... References .......................................................

194 195 201 206 225

8. Vertical distribution of suspended sediment in waves and current over a plane bed 8.1 Vertical distribution of suspended sediment in a steady

current .................................................... 227 8.2 Distribution of suspended sediment in pure oscillatory flow 238 8.3 Vertical distribution of suspended sediment in combined wavecurrent motion ............................................. 250 8.4 Vertical distribution of suspended sediment under broken waves ...................................................... 255 References ...................................................... 257 9. Current-generated bed waves 9.1 Bed waves in current alone ................................. 9.2 Mechanics of dunes in a steady current ..................... 9.3 Influence of waves on current-generated sand waves ......... 9.4 Flow resistance due to bed waves in a current .............. References .............................. .....................

260 265 275 280 287

vii

10. Wave-generated bed forms

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

10.1 Introduction .............................................. 10.2 A simple model for vortex ripples ......................... 10.3 Distribution of suspended sediment over vortex ripples .... References ......................................................

290 293 304 308

11. Cross-shore sediment transport and coastal profile development 11.1 Cross-shore sediment transport ............................ 310 11.2 Development of coastal profile ............................ 318 References ................ ................................... 323

12. Longshore sediment transport and coastline development 12.1 Longshore sediment transport ............................. 325 12.2 Modelling of coastline development ........................ 341 References ...................................................... 347

APPENDIX I. Wave table: Sinusoidal waves ........................... 350 APPENDIX II. Derivation of the k-equation ........................... 352 APPENDIX III. Additional references ................................. 357 SUBJECT INDEX .................................................... 367

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

This page is intentionally left blank

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

Introduction

Flow and sediment transport in the coastal zone are important in relation to several engineering topics like sedimentation and erosion around structures, backfilling of dredged channels, changes in near -shore morphology and long- and cross-shore sediment transport rates. During the last decade the development in coastal sediment transport research has changed from simple phenomenological descriptions to sophisticated numerical models in which the flow as well as the resulting sediment transport are described in detail. The longshore sediment transport calculations can be mentioned as an example. For many years these have been based on the so-called CERC formula (see p 329 ), which relates the longshore sediment rate to the longshore wave energy flux. Today it is recognized that such a simple model which does not include essential parameters like sediment grain size and bed morphology (for instance the presence of bars ) does not give a full description of the complex problem of longshore sediment transport . On the other hand , more sophisticated methods like those described in this book often get very sensitive to variations in the input data , like the mean grain size. The cause might be that the cross -shore profile also varies with the sediment properties , and thus a longshore sediment transport calculation can not be made except with a fully three-dimensional model including grain sorting , a stage which until now has not been reached in the numerical modelling. Another example of the development in coastal sediment transport modelling is the cross - shore profile modelling . Formerly, the average cross-shore profile was described by empirical rules ( Bruun, Dean, see p 322 ), while the trend today is towards describing the on - offshore flow pattern as accurately as possible and then step by step describing the dynamic behaviour of the cross-shore profile by morphological computations . Like the longshore sediment transport calculation, this problem is not completely solved yet - particularly the resulting direction of sediment transport outside the surf zone and the detailed morphology of the bars which must be investigated much more thoroughly.

x Introduction

The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport mechanisms which are of importance for the construction of a mathematical model for sediment transport in coastal areas. The main effort has been to describe the hydrodynamics as is usual in sediment transport description. The first six Chapters deal only with the hydrodynamics of waves and current in and outside the surf zone.

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

The reader's background should be a basic course both in wave hydrodynamics and in fluid mechanics (laminar and turbulent flow). The basic elements of wave hydrodynamics is consequently therefore only briefly listed in the introductory Chapter 1. Chapters 2 and 3 treat the turbulence made by non-breaking waves with and without the presence of a current. During the last decade significant progress has been made in this field, and today very accurate solutions can be obtained. However, these very accurate solutions are also very time-consuming and costly to compute, and it is not feasible today to introduce them in a numerical model of coastal sediment transport. Simpler as well as more advanced solutions to the wave boundary layer problem have therefore been described, from which the bed shear stress in combined wave-current motion can be obtained very accurately. Some of the simpler models are described quite in detail, so students should be able to work with these models on a PC. Chapters 4-6 deal with aspects of surf zone hydrodynamics that are important for the sediment transport. Wave kinematics is described, including the strong production of turbulence in the surf zone which will have to be included in a detailed sediment transport model. The depth-integrated wave-driven currents are treated for more or less complicated situations on uniform coastal profiles, that can be represented by a simple computer model. Furthermore, the flow over complex three-dimensional topographies like rip channels is described. The vertical distribution of the forces from breaking and broken waves is described in detail. This has been applied to model the circulation current (undertow) in the surf zone which is of major importance for cross-shore sediment transport. In Chapter 7 the sediment transport description starts with the basic concepts . The number of sediment transport formulae in current as well as in combined wave-current motion is very large today and rapidly growing. Many of these transport formulae are more or less empirical in their nature, and a simple deterministic description of sediment transport is still not available. In Chapter 7 an attempt is made to describe the construction of a simple transport formula for the bed load case, and some suggestions for the description of sediment transport at higher shear stresses are included as well. However, the sediment transport in the sheet flow layer as well as the bed concentration of suspended sediment are topics which still need to be investigated in more detail. Chapter 8 describes the behaviour of suspended sediment in waves. While the bed load even in this unsteady case usually can be calculated as the quasi-steady value from the instantaneous value of shear stress , the behaviour of suspended sediment gets quite complicated in the wave case due to the increase and decrease in turbulence intensity. Chapters 9 and 10 concern bed waves, which are of major importance for

Introduction

xi

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

the bed shear stress and for the transport of suspended sediment. The description again takes its starting point in the pure current case and extends these findings to the wave case as well. Finally, the last two Chapters 11 and 12 describe the construction of models which can describe long- and cross-shore sediment transport. It is not the intention of the book to give a broad review of the literature on this very wide topic. The structure of the book is more like a monograph where the subjects have been treated so much in detail that the book would be applicable as a student textbook. As a help for further reading on the subject, a section with additional references has been included at the end of the book. The list is far from being complete but should provide students with a good basis for an in-depth study. We would like to acknowledge the encouragement from Professor P.L.-F. Liu to make the book. Our Librarian Kirsten Djorup and Tom Foster, the Danish Hydraulic Institute, have tried to improve our written English. The book has been typewritten in TtX by Hildur Juncker and the drawings are produced by Eva Vermehren. Erik Asp Hansen, Danish Hydraulic Institute, has produced the figure for the front cover, and Julio Zyserman, Danish Hydraulic Institute, has been very helpful in constructing several figures in the book.

Finally we would like to thank the Danish Technical Council (STVF) for their large support to the field of Coastal Engineering in Denmark. This support has created a scientific environment which has made this book possible.

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

This page is intentionally left blank

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

List of symbols

The main symbols used are listed below. Due to the large number of parameters, which stem from different disciplines of hydrodynamics, it has been decided to use double symbols. In most cases their use is restricted to a single chapter as stated in the symbol list. It should be easy to distinguish between these parameters from the context they are used in.

Main symbols a amplitude of near-bed wave orbital motion a migration velocity of bed forms (Chapter 8) A cross-sectional area of the surface rollers (Chapters 4, 5, 6) b level for the reference concentration (Chapter 8)

B wave profile coefficient c wave celerity, phase speed c suspended sediment concentration cb bed concentration C9 wave group velocity c2 turbulent energy dissipation coefficient d grain diameter df grain fall diameter d3 grain sieve diameter

d„ grain spherical diameter d50i d16, d84 diameter corresponding to 50, 16 and 84 percent of the material being finer

D mean water depth D depth-integrated energy dissipation D' boundary layer thickness over the back of a dune D, water depth at the bar crest

xiv

List of symbols

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

e unit vector in x-direction E wave energy E momentum exchange coefficient (Chapter 5) wave energy flux Ef Ef, energy flux due to the surface rollers energy flux due to the wave motion Efw Ek;n kinetic wave energy Epos potential wave energy f friction factor

f () probability density f' skin friction factor current friction factor f^ f^ energy loss factor for the wave boundary layer wave friction factor fw fw wind friction factor (Chapters 5 and 12) F( probability distribution (Chapter 1)

F( error function (Chapter 12) .F Froude number F. momentum contribution to the radiation stress pressure contribution to the radiation stress Fy Fr roller contribution to the radiation stress g acceleration of gravity h local bed level H wave height dune height HD Hr ripple height

Hrms root mean square of the wave heights H. significant wave height II' ax x ax Ho deep water wave height Ho H at x = 0 (Chapter 6) I gradient of the energy line it energy gradient due to skin friction I" energy gradient due to the form resistance of the dunes submerged weight of the longshore sediment transport it k turbulent kinetic energy

k wave number equivalent sand roughness of the bed kN k,,, wave roughness

K ratio between the wave height and the water depth K(Da) directional distribution of wave energy K,: factor in the CERC formula f mixing length Rd turbulent length scale

List of symbols

xv

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

tmax turbulent length scale away from the bed l, length of the surface roller L wave length Lb length of a longshore bar LD dune length L, ripple length Lo deep water wave length M Monin-Obukov parameter Mzy momentum exchange n porosity of the bed sediment p pressure

p fraction of bed surface particles in motion p+ excess pressure above the mean hydrostatic pressure p,. pressure contribution from a surface roller longshore energy flux factor Pt, PROD production of turbulent energy

q discharge per unit width of channel qb bed load transport rate qdrift discharge due to wave drift rate of sediment deposition at a dune front qD specific longshore sediment transport rate qt qroller mean discharge due to surface rollers

q, suspended load transport rate q,d suspended load transport rate due to the wave drift sediment transport rate in the x-direction qax qT specific sediment discharge qo sediment transport rate in the dune trough Q longshore discharge in the trough inshore of a bar Qt longshore sediment transport rate

R Reynold's number Reynold's number for the near-bed wave-orbital motion RE s relative density of the sediment s parameter in expression for directional wave spreading (Chapters 5and12) S„„ total wave momentum flux in the direction normal to the direction of wave propagation S„ total wave momentum flux in the direction of wave propagation normal radiation stress in the x-direction S..

shear component of the radiation stress Spy normal radiation stress in the y-directioll Syy S mean water surface slope t time T wave period

T. significant wave period

xvi

List of symbols

u velocity in the x-direction

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

U f friction velocity, time varying uj Lagrangian wave drift velocity us streaming induced velocity uz, velocity in the x'-direction uo free stream wave- orbital velocity near the bed U wave period averaged velocity

velocity of grain in bed load transport UB friction velocity, steady Uf skin friction velocity Uf current friction velocity Ufc U1 1: critical friction velocity ( Chapter 7) U f max maximum friction velocity during wave period

Ufo friction velocity for the mean velocity profile in the wave boundary layer mean current velocity at the top of a wave boundary layer Ua Ulm amplitude of near- bed wave-orbital velocity ( 1st order Stokes theory) Ulm amplitude of second harmonic of the near -bed wave orbital velocity

Uio wind speed 10 m above the sea surface v velocity in the y-direction vy , velocity in the y'-direction V depth mean velocity V' local depth mean velocity depth mean velocity in the x-direction V. Vv depth mean velocity in the y-direction V' mean velocity in the boundary layer over a dune w velocity in the z-direction

w' dimensionless settling velocity terminal settling velocity of a sediment grain ws woo vertical velocity due to the displacement in a wave boundary layer x horizontal coordinate x' horizontal coordinate y horizontal coordinate y' horizontal coordinate

Y position of the coastline Yb width of a rip channel z vertical coordinate zC height of the centroid of a suspended sediment concentration profile zo zero level for velocity ( kN130 at a rough bed) a wave direction aw wind direction

List of ofsymbols symbols List List of symbols

xvii xvii xvii

deep wave water direction ao direction ao deep deep water water wavewave direction 5) slope of theboundary lower boundary a surface roller (((Chapters Chapters ao lower of surface roller Chapters 44 and and 5) 5) ao slope slope of of the the lower boundary of a aof surface roller slopeangle angle of of the thecoastal coastalprofile profile or transverse to mean bed bed slope slope angle of the coastal profile or transverse transverse to the the mean mean current direction direction current current direction

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

ratio between between Ee,, and and vT VT (Chapter (Chapter 8) 8) ratio ratio between e, and vT (Chapter 8) specific gravity pg ry gravity pg ry specific specific gravity pg angle of slope the bedin the mean current direction ry bed the mean current direction ry angle angle of of the the bed slope inslope the in mean current direction Chapters angle between the current andwave the wave propagation (((Chapters ry the and propagation Chapters 333 ry angle angle between between the current current and the the wave propagation and 8) 8) and 8) specific gravity the sediment grains ry, of grains ry, specific gravity gravity of the theofsediment sediment grains 7 s specific wave boundary thickness S wave S layer thickness S wave boundary boundary layerlayer thickness displacement thickness S* displacement S* thickness S* displacement thickness mean of theboundary wave boundary layer thickness 5,, of the layer thickness 5,, mean value value of value the wave wave boundary layer thickness srn mean sheet layer thickness S, thickness S, sheet layer layer thickness 6s sheet sublayer thickness the viscous b" of viscous sublayer b" thickness of the theof viscous sublayer 6" thickness wave set-up or set-down A D wave OD or OD wave set-up set-up or set-down set-down hydraulic head loss AH hydraulic OH head loss OH hydraulic head loss hydraulic at dune front AH" hydraulic LH" head loss at front LH" hydraulic headhead lossloss at dune dune front At time step At time step At time step

Ax step Ox in Ox stepstep ininx xx Y AY step AY in AY stepstep ininY Y deviation from mean wave direction Acu deviation Da from wave direction Da deviation from mean mean wave direction in thestress shear over stressaaover a wave boundary layerdue dueto to Or the wave boundary layer AT change Or change in inchange the shear shear stress over wave boundary layer due to streaming streaming streaming dissipation of turbulent energy e of energy e dissipation dissipation of turbulent turbulent energy apparent turbulent turbulent diffusion diffusioncoefficient coefficient apparent apparent turbulent diffusion coefficient turbulent diffusion diffusion coefficient coefficient for for sediment sediment turbulent turbulent diffusion coefficient for sediment hydraulic head headloss losscoefficient coefficient hydraulic hydraulic head loss coefficient parameter,,, dimensionless dimensionlessbed stress 9 parameter dimensionless bed shear shear stress stress 9 Shields' Shields'Shields' parameter dimensionless bed shear stress, skin friction of bed stress, skin friction of dimensionless dimensionless bed shear shear stress, skin friction dimensionless drag dunes o" form drag on dunes o" dimensionless dimensionless formform drag onon dunes 8 at dune surface localof value of dune o* 9 surface o* local local value value of 9 at at dune surface critical Shields' parameter oc parameter oc critical critical Shields' Shields' parameter

(=221-0c) $8,) dimensionlessparameter parameter(;^dimensionless dimensionless dimensionless parameter (;^1-0c) dimensionless Shields''' parameter parameter corrected corrected for bed slope slope ory parameter corrected for aa a bed bed slope ory Shields Shields water surface elevation 77 elevation 77 water water surface surface elevation surface roller roller thickness thickness rl+ surface rl+ surface roller thickness hconstant ' s constant von K b m constant K K von von Karman's Karman's linear sediment concentration A concentration A linear linear sediment sediment concentration dynamic viscosity µ viscosity µ dynamic dynamic viscosity dynamicfriction frictioncoefficient coefficient dynamic µd dynamic friction coefficient µd static friction coefficient AS coefficient AS static static friction friction coefficient kinematic viscosity v viscosity v kinematic kinematic viscosity eddy viscosity viscosity eddy eddy viscosity VT VT

Mechanics of Coastal Sediment Transport Downloaded from www.worldscientific.com by 37.44.207.4 on 01/29/17. For personal use only.

xviii

£ p pa