Large-Eddy Simulation in Hydraulics

by Wolfgang Rodi, George Constantinescu, Thorsten Stoesser

Overview

Large-Eddy Simulation (LES), which is an advanced eddy-resolving method for calculating turbulent flows, is used increasingly in Computational Fluid Dynamics, also for solving hydraulics and environmental flow problems. The method has generally great potential and is particularly suited for problems dominated by large-scale turbulent structures. This book gives an introduction to the LES method specially geared for hydraulic and environmental engineers. Compared with existing books on LES it is less theoretically and mathematically demanding and hence easier to follow, and it covers special features of flows in water bodies and summarizes the experience gained with LES for calculating such flows.

The book was written primarily as an introduction to LES for hydraulic and environmental engineers, but it will also be very useful as an entry to the subject of LES for researchers and students in all fields of fluids engineering. The applications part will further be useful to researchers interested in the physics of flows governed by the dynamics of coherent structures.

Product Details

ISBN-13:	9780203797570
Publisher:	CRC Press
Publication date:	06/27/2013
Series:	IAHR Monographs
Sold by:	Barnes & Noble
Format:	eBook
Pages:	266
File size:	123 MB
Note:	This product may take a few minutes to download.

About the Author

Wolfgang Rodi studied Aeronautical Engineering at the University of Stuttgart and received his Ph.D. degree in Mechanical Engineering from Imperial College, London, where he played a major role in the development of turbulence models that are now widely used in practice. In 1973 he moved to Karlsruhe University where he has been a Professor in Civil Engineering from 1981 until 2007, when he retired from this position. At Karlsruhe he pioneered the application of turbulence models in hydraulics but was also active in their extensive testing in other areas of engineering. In the 1990’s he shifted his interest to large eddy simulations of complex flows including those in hydraulics. He also supervised experiments that resulted in widely used benchmark test cases for calculation methods. Prof. Rodi published more than 100 journal papers and several monographs on turbulence modelling. He is an Associate Editor of the ASCE Journal of Hydraulic Engineering and an Editor of the Journal of Flow, Turbulence and Combustion. He has won several prestigious awards including the IAHR Ippen Award, the ASCE Hunter Rouse Hydraulic Engineering Lecture Award and the ASME Fluids Engineering Award. Since 2011 he is Distinguished Adjunct Professor at King Abdulaziz University, Jeddah, Saudi Arabia.

George Constantinescu obtained his first degree from the Civil Engineering Institute in Bucharest, Romania and his Ph.D. in Hydraulics from the University of Iowa, USA, in 1997. For the next 5 years he held post-doctoral positions with the Arizona State University and the Center for Turbulence Research, Stanford University. In 2004, he joined the Department of Civil and Environmental Engineering at the University of Iowa as an Assistant Professor and is currently an Associate Professor at the same university. Prof. Constantinescu has expertise in numerical simulations of complex turbulent flows using a wide range of modelling techniques and large-scale parallel computing. His present main research interests are in river restoration and modelling of stratified flows, shallow flows, flow and transport processes around hydraulic structures, sediment transport and morphodynamics in alluvial channels, flows in porous media. Prof Constantinescu is an Associate Editor of the ASCE Journal of Hydraulic Engineering and of the IAHR Journal of Hydraulic Research and the chairman of the IAHR Fluid Mechanics Committee. He co-authored 55 journal papers in the area of environmental fluid mechanics and hydraulics. He received two ASCE EWRI awards for Best Technical Note (2001) and in 2011 the Karl Emil Hilgard Hydraulic Prize for Best Paper in the ASCE Journal of Hydraulic Engineering.

Thorsten Stoesser studied Civil Engineering at the University of Karlsruhe and obtained his Ph.D. in this field from the University of Bristol in 2001. In 2006, after 5 years of post-doctoral research at the Institute of Hydromechanics at the University of Karlsruhe, he took up an Assistant Professorship at the Georgia Institute of Technology, Atlanta, USA, where he got promoted to Associate Professor shortly before he moved in May 2012 to take up his current position as Professor in the Hydro-environmental Research Centre at Cardiff University, UK. His expertise includes turbulence modelling via large eddy simulation (LES), rough-bed and vegetation hydrodynamics and advancing computational methods to study numerically fluid structure interaction. Prof. Stoesser has published 26 journal papers and two book chapters on developing, testing and applying Computational Fluid Dynamics methods to investigate hydrodynamics and turbulence in open-channel flow and has recently delivered keynote lectures on the subject at workshops and conferences. He is an Associate Editor of the IAHR Journal of Hydraulic Research. In 2012 he received the ASCE Karl Emil Hilgard Hydraulic Prize for his paper on "LES of flow through vegetation".

Table of Contents

Preface

1 Introduction

1.1 The role and importance of turbulence in hydraulics

1.2 Characteristics of turbulence

1.3 Calculation approaches for turbulent flows

1.4 Scope and outline of the book

2 Basic methodology of LES

2.1 Navier-Stokes equations and Reynolds Averaging (RANS)

2.2 The idea of LES

2.3 Spatial filtering/averaging and resulting equations

2.4 Implicit filtering and Schumann’s approach

2.5 Relation of LES to DNS and RANS

3 Subgrid-Scale (SGS) models

3.1 Role and desired qualities of an SGS-model

3.2 Smagorinsky model

3.3 Improved versions of eddy viscosity models

3.4 SGS models not based on the eddy viscosity concept

3.5 SGS models for the scalar transport equation

4 Numerical methods

4.1 Introduction

4.2 Discretization methods

4.3 Numerical accuracy in LES

4.4 Numerical errors

4.5 Solution methods for incompressible flow equations

4.6 LES grids

5 Implicit LES (ILES)

5.1 Introduction

5.2 Rationale for ILES and connection with LES using explicit SGS models

5.3 Adaptive Local Deconvolution Model (ALDM)

5.4 Monotonically Integrated LES (MILES)

6 Boundary and initial conditions

6.1 Periodic boundary conditions

6.2 Outflow boundary conditions

6.3 Inflow boundary conditions

6.4 Free surface boundary conditions

6.5 Smooth-wall boundary conditions

6.6 Rough-wall boundary conditions

6.7 Initial conditions

7 Hybrid RANS-LES methods

7.1 Introduction

7.2 Two-layer models

7.3 Embedded LES

7.4 Detached Eddy Simulation (DES) models

7.5 Scale-Adaptive Simulation (SAS) model

7.6 Final comments on hybrid RANS-LES models and future trends

8 Eduction of turbulence structures

8.1 Structure eduction from point signals: Two-point correlations and velocity spectra

8.2 Structure eduction from instantaneous quantities in 2D planes

8.3 Structure eduction from isosurfaces of instantaneous quantities in 3D space

9 Application examples of LES in hydraulics

9.1 Developed straight open channel flow

9.2 Flow over rough and permeable beds

9.3 Flow over bedforms

9.4 Flow through vegetation

9.5 Flow in compound channels

9.6 Flow in curved open channels

9.7 Shallow merging flows

9.8 Flow past in-stream hydraulic structures

9.9 Flow and mass exchange processes around a channel-bottom cavity

9.10 Gravity currents

9.11 Eco-hydraulics: Flow past an array of freshwater mussels

9.12 Flow in a water pump intake

Appendix A – Introduction to tensor notation

References

Index

Editorial Reviews

"Large-Eddy Simulation in Hydraulics is recommended to numerical modellers working on turbulent flow problems in any branch of hydraulics. To quote William Cowper (The Task: A Poem in Six Books, Book III, The Garden, 1785)

A life all turbulence and noise may seem,
To him that leads it, wise and to be praised;
But wisdom is a pearl with most success
Sought in still water, and beneath clear skies.

Overall, the authors are to be congratulated on producing a wise textbook that is timely, very informative and covers a topic of great importance in modern fluid mechanics."

A.G.L. Borthwick, Proceedings of the Institution of Civil Engineers, Engineering and Computational Mechanics 167, March 2014, Issue EM1

"Large-Eddy Simulation in Hydraulics is recommended to numerical modellers working on turbulent flow problems in any branch of hydraulics. To quote William Cowper (The Task: A Poem in Six Books, Book III, The Garden, 1785)

A life all turbulence and noise may seem,
To him that leads it, wise and to be praised;
But wisdom is a pearl with most success
Sought in still water, and beneath clear skies.

Overall, the authors are to be congratulated on producing a wise textbook that is timely, very informative and covers a topic of great importance in modern fluid mechanics."

A.G.L. Borthwick, in: Proceedings of the Institution of Civil Engineers, Engineering and Computational Mechanics 167, March 2014, Issue EM1

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