Turbulent Drag Reduction by Surfactant Additives

Preface ix 1 Introduction 1 1.1 Background 1 1.2 Surfactant Solution 4 1.2.1 Anionic Surfactant 6 1.2.2 Cationic Surfactant 6 1.2.3 Nonionic Surfactant 7 1.2.4 Amphoteric Surfactant 7 1.2.5 Zwitterionic Surfactant 7 1.3 Mechanism and Theory of Drag Reduction by Surfactant Additives 8 1.3.1 Explanations of the Turbulent DR Mechanism from the Viewpoint of Microstructures 8 1.3.2 Explanations of the Turbulent DR Mechanism from the Viewpoint of the Physics of Turbulence 10 1.4 Application Techniques of Drag Reduction by Surfactant Additives 14 1.4.1 Heat Transfer Reduction of Surfactant Drag-reducing Flow 15 1.4.2 Diameter Effect of Surfactant Drag-reducing Flow 15 1.4.3 Toxic Effect of Cationic Surfactant Solution 15 1.4.4 Chemical Stability of Surfactant Solution 15 1.4.5 Corrosion of Surfactant Solution 16 References 16 2 Drag Reduction and Heat Transfer Reduction Characteristics of Drag-Reducing Surfactant Solution Flow 19 2.1 Fundamental Concepts of Turbulent Drag Reduction 19 2.2 Characteristics of Drag Reduction by Surfactant Additives and Its Influencing Factors 22 2.2.1 Characteristics of Drag Reduction by Surfactant Additives 23 2.2.2 Influencing Factors of Drag Reduction by Surfactant Additives 27 2.3 The Diameter Effect of Surfactant Drag-reducing Flow and Scale-up Methods 31 2.3.1 The Diameter Effect and Its Influence 31 2.3.2 Scale-up Methods 32 2.3.3 Evaluation of Different Scale-up Methods 43 2.4 Heat Transfer Characteristics of Drag-reducing Surfactant Solutionm Flow and Its Enhancement Methods 47 2.4.1 Convective Heat Transfer Characteristics of Drag-reducing Surfactant Solution Flow 47 2.4.2 Heat Transfer Enhancement Methods for Drag-reducing Surfactant Solution Flows 50 References 59 3 Turbulence Structures in Drag-Reducing Surfactant Solution Flow 63 3.1 Measurement Techniques for Turbulence Structures in Drag-Reducing Flow 64 3.1.1 Laser Doppler Velocimetry 64 3.1.2 PIV 66 3.2 Statistical Characteristics of Velocity and Temperature Fields in Drag-reducing Flow 68 3.2.1 Distribution of Averaged Quantities 69 3.2.2 Distribution of Fluctuation Intensities 74 3.2.3 Correlation Analyses of Fluctuating Quantities 77 3.2.4 Spectrum Analyses of Fluctuating Quantities 78 3.3 Characteristics of TurbulentVortex Structures in Drag-reducing Flow 83 3.3.1 Identification Method of Turbulent Vortex by Swirling Strength 84 3.3.2 Distribution Characteristics of Turbulent Vortex in the x-y Plane 85 3.3.3 Distribution Characteristics of Turbulent Vortex in the y-z Plane 87 3.3.4 Distribution Characteristics of Turbulent Vortex in the x-z Plane 90 3.4 Reynolds Shear Stress and Wall-Normal Turbulent Heat Flux 96 References 100 4 Numerical Simulation of Surfactant Drag Reduction 103 4.1 Direct Numerical Simulation of Drag-reducing Flow 104 4.1.1 A Mathematical Model of Drag-reducing Flow 104 4.1.2 The DNS Method of Drag-reducing Flow 109 4.2 RANS of Drag-reducing Flow 111 4.3 Governing Equation and DNS Method of Drag-reducing Flow 114 4.3.1 Governing Equation 114 4.3.2 Numerical Method 117 4.4 DNS Results and Discussion for Drag-reducing Flow and Heat Transfer 122 4.4.1 The Overall Study on Surfactant Drag Reduction and Heat Transfer by DNS 122 4.4.2 The Rheological Parameter Effect of DNS on Surfactant Drag Reduction 160 4.4.3 DNS with the Bilayer Model of Flows with Newtonian and Non-Newtonian Fluid Coexistence 173 4.5 Conclusion and Future Work 178 References 179 5 Microstructures and Rheological Properties of Surfactant Solution 183 5.1 Microstructures in Surfactant Solution and Its Visualization Methods 183 5.1.1 Microstructures in Surfactant Solution 183 5.1.2 Visualization Methods for Microstructures in Surfactant Solution 187 5.2 Rheology and Measurement Methods of Surfactant Solution 189 5.2.1 Rheological Parameters 190 5.2.2 Measurement Method of Rheological Parameters 194 5.2.3 Rheological Characteristics of Dilute Drag-reducing Surfactant Solution 200 5.3 Factors Affecting the Rheological Characteristics of Surfactant Solution 207 5.3.1 Surfactant Concentration 207 5.3.2 Temperature 208 5.3.3 Type of Surfactant 208 5.4 Characterization of Viscoelasticity of Drag-reducing Surfactant Solution by Using Free Surface Swirling Flow 209 5.5 Molecular and Brownian Dynamics Simulations of Surfactant Solution 216 5.5.1 Brief Introduction of Simulation Methods 216 5.5.2 Brownian Dynamics Simulation by Using a WK Potential 221 References 231 6 Application Techniques for Drag Reduction by Surfactant Additives 233 6.1 Problems That Need to Be Solved in Engineering Applications 233 6.1.1 Influencing Factors of Drag-reducing Surfactant Additives on the Heat Transfer Performance of Heat Exchangers and Its Counter-measures 234 6.1.2 Influences of Drag-reducing Surfactant Additives on the Environment 235 6.1.3 Scale-up Problem 236 6.2 Separation Techniques for Surfactant Solution 237 6.2.1 Adsorption 238 6.2.2 Ultrafiltration 238 6.2.3 Reverse Osmosis 239 6.3 Drag Reduction Stability of Surfactant Solutions 239 6.3.1 Effect of Adsorption 239 6.3.2 Effects of Fe(OH)3 240 6.3.3 Effects of Cu(OH)2 241 6.3.4 Recovery of Drag Reduction 241 6.4 Applications of Surfactant Drag Reduction 242 6.4.1 Application of Surfactant to Hydronic Heating and Air-Conditioning Systems 242 6.4.2 Surfactant Selection in Actual Applications 251 References 253 Index 255