IUTAM Symposium on Advances in Micro- and Nanofluidics (eBook)

Preface 6
Contents 7
List of Contributors 9
Part I Plenary Lectures 12
Nonlinear Electrokinetic Flow: Theory, Experiment, and Potential Applications 13
Introduction 13
Concentration Polarization (CP) and Over-Limiting Current 15
Nonlinear Electrokinetic Flow Near Perm-Selective Nanochannels 18
Outlook 24
Acknowledgement 25
References 25
Fluid Particle Models for the Simulation of Microfluids 28
Introduction 28
Dissipative Particle Dynamics 30
Smoothed Dissipative Particle Dynamics 31
Microstructured Fluids Modelling 33
Colloidal Particle 33
Polymer Molecule 34
Simulations 35
Colloidal Particle in Suspension 35
Polymer Molecule in Suspension 37
Conclusions 39
References 40
Part II Micro-channel Flows 41
Semi-analytical Solution of the Density Profile for a Gas Close to a Solid Wall 42
Introduction 42
MD Derivation of Equation of State 44
Internal Force 44
Pressure 45
MD Calculation Method 46
Equation of State Results 47
Analytical Derivation of Equilibrium State 49
Method to Calculate the Equilibrium Density 49
Simplifications at the Wall 50
Numerical Aspects 50
Equilibrium Results 51
Summary 54
Acknowledgment 56
References 56
Comprehensive Analysis of Dewetting Profiles to Quantify Hydrodynamic Slip 58
Introduction 58
Slippage at Solid/Liquid Interfaces 58
Dewetting Dynamics of Polymer Films 59
Experimental Section 60
Our System 60
Hole Growth Dynamics 60
Rim Shapes 62
Theoretical Models and Data Analysis 62
Lubrication Model 62
Stokes Model 65
Method to Extract Slip Length and Capillary Number 66
Experimental Tests 67
Results and Discussion 68
Conclusion 70
Acknowledgments 71
References 71
Variation of Transport Properties Along Nanochannels: A Study by Non-equilibrium Molecular Dynamics 73
Introduction 73
Description of the Simulation System 74
Computational Details 75
Results and Discussion 76
Conclusions 83
Acknowledgement 84
References 84
Estimation of the Poiseuille Number in Gas Flows Through Rectangular Nano- and Micro-channels in the Whole Range of the Knudsen Number 85
Introduction 85
Flow Configuration 86
Formulation 87
Results and Discussion 90
Concluding Remarks 92
References 92
Moving Contact Line with Balanced Stress Singularities 93
Introduction 93
Smoothed, Finite-Width Interface Model for Moving Contact Line 94
Discussion 97
Conclusion 99
References 99
Part III Complex Fluids 101
Clarification and Control of Micro Plasma Flow with Wall Interaction 102
Introduction 102
Electric Propulsion 102
Hall-effect Accelerator 103
Phenomena in Micro Plasma Flow 104
Numerical Analysis 105
Fundamental Equations 105
Boundary Conditions 107
Results and Discussion 107
Plasma Instability 107
Average Length of Ionization-Zone 108
Parametric Estimations of Instability and Performances 109
Spatiotemporal Variations of Plasma Parameters and Electromagnetic Field 112
Influence of Fixed Parameters upon Calculations 114
New Concept for the Higher Performance 115
Conclusions 117
Acknowledgments 117
References 117
Electrochemical Control of the Surface Energy of Conjugated Polymers for Guiding Samples in Microfluidic Systems 118
Introduction 118
pi-Conjugated Polymers 119
Electrochemical Doping 120
Chemical Process 121
Chemical Property Changes 121
Device Structure 122
Wettability 122
Direct 122
Surfactant 123
Experimental Data 125
Application in Fluidics 125
Analyte as Electrolyte 126
Secondary Electrolyte 127
Extension to Smaller Dimensions 128
Integration with Sensing Devices 129
Challenges 129
Conclusion 129
Acknowledgements 130
References 130
Small Scale Cavitation Model 131
Introduction 131
Description of the Internal Structure of the Continuum 133
The Micro Mechanics Evolution Equation 134
The Regular Micro Flow 134
No Nucleation Hypothesis 134
With Nucleation 135
The Non Regular Micro Flow 136
Numerical Approximation 137
Direct Method 137
Inverse Method 138
Case Studies 139
Linearly Decreasing History of Pressures. Explosive growth 140
Linearly Increasing History of Pressures. Collapse and Growth 143
Conclusions 145
Nomenclature 146
References 147
Experimental and Theoretical Approach for Analysis of Flow Induced by Micro Organisms Existing on Surface of Granular Activated Sludge 148
Introduction 148
Materials and Methods 150
Results 151
Conclusions 154
References 156
Part IV Numerical Modeling 157
Coupling Atomistic and Continuum Descriptions Using Dynamic Control 158
Introduction 158
Methodology 159
Couette Flow 163
Conclusions 165
References 165
Lattice Boltzmann Simulation of Pulsed Jet in T-Shaped Micromixer 167
Introduction 167
Numerical Procedure 168
Lattice Boltzmann Method 168
Results 169
Two Dimensional Pulsed Jet 169
The Computational Details 169
Single Pulsed Jet 170
Opposite Pulsed Jets 170
Pulsed Jets in Parallel 172
Three Dimensional Pulsed Jet 173
Conclusions 174
References 174
Simulation of High-Speed Flow in µ-Rockets for Space Propulsion Applications 175
Introduction 175
Numerical Method 176
Continuum-Based Simulation 176
Higher-Order Slip-Model 177
Flow Conditions and Model Validation 179
Conical Nozzle 180
3D-Flat Nozzle 181
Results and Discussion 182
Viscous Heating 182
Nozzle Performance 184
Conclusions 188
Acknowledgements 189
References 189
Numerical Study on the Flow Physics of a T-Shaped Micro Mixer 190
Introduction 190
Method 191
The Model 191
Numerical Schemes 192
Results 193
The Differencing Scheme 193
The Spatial Resolution 193
The Channel-Inlet Length 195
The Flow Topology 197
The Reflectional-Symmetric Flow 197
The Rotational-Symmetric Flow 198
The Reynolds Number of Flow Transition 200
The Transition Region Between Diffusive and Convective Mixing 200
Conclusions 202
References 203
Splitting for Highly Dissipative Smoothed Particle Dynamics 205
Introduction 205
Model 206
Mesoscopic Modeling of the Liquids 206
Time Step Limitations 208
Implicit Integration Scheme 208
Validation of the Scheme for Macroscopic Flow 210
Poiseuille Flow 210
Couette Flow 211
Temperature Control 212
Schmidt Number 213
References 215