An expert review of recent progress in the study of turbulent flows with a focus on recently identified organized structures. This book reviews the recent progress in the study of the turbulent flows that sculpt the Earths surface, focusing in particular on the organized structures that have been identified in recent years within turbulent flows. These coherent flow structures can include eddies or vortices at the scale of individual grains, through structures that scale with the flow depth in rivers or estuaries, to the large-scale structure of flows at the morphological or landform scale. These flow structures are of wide interest to the scientific community because they play an important role in fluid dynamics and influence the transport, erosion and deposition of sediment and pollutants in a wide variety of fluid flow environments.

Scientific knowledge of these structures has improved greatly over the past 20 years as computational fluid dynamics has come to play an increasing important part in building our understanding of coherent flow structures across a broad range of scales.

Chapters comprise a series of major, invited papers and a selection of the most novel, innovative papers presented at the second Coherent Flow Structures Conference held August 3-5, 2011 at Simon Fraser University in Burnaby, British Columbia.

Chapters focus on six major themes:

Dynamics of coherent flow structures (CFS) in geophysical flowsInteraction of turbulent flows, vegetation and ecological habitatsCoherent structure of atmospheric flowsNumerical modeling of coherent flow structuresTurbulence in open channel flowsCoherent flow structures, sediment transport and morphological feedbacks.

Jeremy G. Venditti, Assistant Professor, Simon Fraser University, Department of Geography, Burnaby, British Columbia, Canada.

James L. Best, Threet Professor, Departments of Geology and Geography, University of Illinois, Urbana, IL, USA.

Michael Church, Professor emeritus, Department of Geography, The University of British Columbia, Vancouver, British Columbia, Canada.

Richard J. Hardy, Lecturer, Department of Geography, Durham University, UK.

List of Contributors, vii

Preface, xi

About the Companion Website, xiii

1 What is a Coherent Flow Structure in Geophysical Flow? 1Jeremy G. Venditti, Richard J. Hardy, Michael Church,& James L. Best

2 Structure of Turbulent Boundary Layers 17Ronald J. Adrian

3 Structural Attributes of Turbulent Flow over a Complex Topography 25Ricardo Mejia-Alvarez, Julio M. Barros,& Kenneth T. Christensen

4 Coherent Flow Structures in the Pore Spaces of Permeable Beds underlying a Unidirectional Turbulent Boundary Layer: A Review and some New Experimental Results 43Gianluca Blois, James L. Best, Kenneth T. Christensen, Richard J. Hardy,& Gregory H. Sambrook Smith

5 Instabilities in Stratified Shear Flow 63Gregory A. Lawrence, Edmund W. Tedford,& Jeffrey R. Carpenter

6 Scalar Turbulence within the Canopy Sublayer 73Gabriel G. Katul, Daniela Cava, Mario Siqueira,& Davide Poggi

7 On the Structure of Wall Turbulence in the Thermally Neutral Atmospheric Surface Layer 97Michele Guala, Jeff LeHew, Meredith Metzger,& Beverley J. McKeon

8 Critical Reflections on the Coherent Flow Structures Paradigm in Aeolian Geomorphology 111Bernard O. Bauer, Ian J. Walker, Andreas C.W. Baas, Derek W.T. Jackson, Cheryl McKenna Neuman, Giles F.S. Wiggs,& Patrick A. Hesp

9 Coherent Flow Structures in Vegetated Channels 135Heidi Nepf, Jeffrey Rominger,& Lijun Zong

10 Coherent Eddy Structures over Plant Canopies 149Roger H. Shaw, Edward G. Patton,& John J. Finnigan

11 SPIV Analysis of Coherent Structures in a Vegetation Canopy Model Flow 161Laurent Perret& Tony Ruiz