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Wall Turbulence Control

Wall Turbulence Control

Sedat Tardu

ISBN: 978-1-119-00905-4

Feb 2017, Wiley-ISTE

198 pages

$96.99

Description

Wall turbulence control is a major subject, the investigation of which involves significant industrial, environmental and fundamental consequences. Wall Turbulence Control addresses recent advances achieved in active and passive wall turbulence control over the past two decades. This valuable reference for scientists, researchers and engineers provides an updated view of the research into this topic, including passive control, optimal and suboptimal control methodology, linear control and control using adaptive methods (neural networks), polymer and bubble injection, electromagnetic control and recent advances in control by plasma.
Preface vii

Notations  ix

Chapter 1. General Points  1

1.1. Introduction  1

1.2. Tools to analyze and develop control strategies 2

1.2.1. Numerical simulations 2

1.2.2. Sensors 3

1.2.3. Actuators 20

Chapter 2. Summary of the Main Characteristics of Wall Turbulence 23

2.1. Introduction  23

2.2. General equations 23

2.2.1. Eulerian relations  24

2.3. Notations  25

2.4. Reynolds equations  26

2.5. Exact relations and FIK identity  27

2.6. Equations for a turbulent boundary layer 32

2.7. Scales in a turbulent wall flow 34

2.8. Turbulent viscosity closures  35

2.9. Turbulent intensities of the velocity components  47

2.10. Vorticity and near wall coherent structures 51

Chapter 3. Passive Control  65

3.1. Introduction 65

3.2. Large eddy (outer layer) breakup devices, LEBUs (OLDs) 66

3.2.1. General 66

3.2.2. Alteration of the inner structure by outer layer devices  67

3.3. Riblets  72

3.3.1. General 72

3.3.2. Effect of the riblets on the fine structure of wall turbulence 76

3.3.3. Effect of the protrusion height 84

3.4. Superhydrophobic surfaces  93

Chapter 4. Active Control 99

4.1. Introduction 99

4.2. Local blowing 100

4.3. Ad-hoc control 107

4.4. Transverse wall oscillations 115

4.5. Alternated spanwise Lorenz forcing and electromagnetic (EM) control  123

4.6. Extensions of spanwise forcing 131

4.7. Reynolds number dependence  132

4.8. Suboptimal active control  134

4.9. Optimal active control  143

4.10. Optimal linear control  147

4.11. Neural networks 156

4.12. Stochastic synchronization of the wall turbulence and dual control 157

Bibliography  167

Index 185