Flow Visualization in Materials Processing (eBook)

Prof. Manabu is the author of the following books published by Springer. 'Modeling Multiphase Materials Processes, ISBN 978-1-4419-7478-5' 'Basic Transport Phenomena in Materials Processing, ISBN 978-4-431-54019-9

Preface 6
Acknowledgements 8
Contents 9
Acronyms 13
Fundamentals 14
1 Introduction 15
Abstract 15
1.1 Multi-phase Flow and Enhancement of Metallurgical Reactions in Materials Processing 15
1.2 Bubble Shape on Related Dimensionless Variables 21
1.2.1 Shape of a Single Bubble Rising in a Still Liquid 21
1.2.2 Shape of a Bubble Rising in a Bubbling Jet 22
1.3 Earlier Works on Gas/Liquid and Immiscible Two Liquid Multi-phase Flows 23
1.3.1 Refining Processes 24
1.3.2 Casting Processes 25
1.4 Some Related Problems on Wettability 26
1.5 Historical Progress of Visualization Techniques 27
References 27
2 Fundamentals of Experimental Visualization 30
Abstract 30
2.1 Generation Method of Bubble and Droplet 30
2.1.1 Generation Method of Bubble 30
2.1.2 Generation Method of Droplet 37
2.2 Experimental Setup 38
2.2.1 Design of Nozzle and Its Mount for Visualization 38
2.2.2 Setup of Illumination for Visualization 39
2.3 Seeding Particle 39
2.4 Image Analysis 40
2.4.1 Introductory Remarks 40
2.4.2 Classification of PIV 41
2.4.2.1 Multiple Exposure Techniques 41
2.4.2.2 Method Using Consecutive Time-Step Patterns 43
2.4.3 High-Speed Algorithm Based on Binary Cross-Correlation Method 45
2.4.3.1 Two-Dimensional Particle Tracking Velocimetry (2D PTV) 45
2.4.3.2 Three-Dimensional Particle Tracking Velocimetry (3D PTV) 56
2.4.4 Concluding Remarks 57
References 57
Applications—Multi-phase Flow and Its Visualized Examples in Materials Processing 60
3 Visualization of Flow Induced by Bubble Dispersion 61
Abstract 61
3.1 Shape and Size of Bubble Detaching at Single-Hole Nozzle 61
3.1.1 Generation of Bubble at a Single-Hole Nozzle 61
3.1.2 Generation of Bubble at a Wetted Single-Hole Nozzle (0° ? ?  lessthan  90°) 63
3.1.3 Generation of Bubble at a Poorly Wetted Single-Hole Nozzle (90°? ? ? 180°) 64
3.2 Interaction of Bubbles Near a Nozzle 65
3.3 Flow Around Single Rising Bubble 67
3.4 Merging of Two Bubbling Jets 69
References 71
4 Jet-Induced Rotary Sloshing in a Cylindrical Container 73
4.1 Fundamentals 74
4.1.1 Fundamental Theory of Rotary Sloshing 74
4.1.2 Characteristics of Jet-Induced Rotary Sloshing 78
4.1.3 Model of Occurrence Condition 89
References 98
5 Behavior of a Rising Bubble Through an Oil/Water Interface 99
5.1 Scenario of a Rising Bubble Through Oil/Water Interface 99
5.1.1 Experimental Setup 100
5.1.2 Computational Procedure 101
5.1.3 Results and Discussion 101
5.1.4 Summary 107
5.2 Observation of a Bubble Surface During the Passage of the Bubble Through an Oil/Water Interface 108
5.2.1 Backgrounds 108
5.2.2 High-Speed Photography and Index Matching Visualization 109
5.2.3 Results and Discussion 110
5.2.4 Summary 115
5.3 Influence of Oppositely Charged Oil/water Interface 117
5.3.1 Backgrounds 117
5.3.2 Experimental Setup and Procedure 118
5.3.3 Results and Discussion 119
5.3.4 Summary 123
5.4 Closing Remarks 123
References 124
6 Continuous Casting of Molten Steel 126
Abstract 126
6.1 Introductory Remarks 126
6.2 Flow in Tundish 128
6.3 Flow in Immersion Nozzle 128
6.4 Mechanism of Mold Powder Entrapment in Mold 129
6.5 Removal of Nonmetallic Inclusions in Immersion Nozzle 143
6.6 Concluding Remarks 144
References 144
7 Wettability Problems in Materials Processing 145
7.1 Wettability and Water-Repellent Material 145
7.1.1 Young's Equation and Models of Wenzel and Cassie--Baxter 145
7.1.2 Several Topics of Dynamic Contact Angle 152
7.1.3 Microscope Observation of a Droplet Surface on a Plate by Spray-Coating of a Water-Repellent Material 159
7.1.4 Slip Velocity on a Superhydrophobic Wall Surface in a Laminar Pipe Flow 161
7.2 Water Entry of Hydrophobic Objects 166
7.2.1 Historical Background 166
7.2.2 Cavity Formation and Equation of Motion for Spheres Entering into Water 167
7.2.3 Cavity Dynamics for Hydrophobic Circular Cylinders 170
7.3 A Bouncing Droplet on a Superhydrophobic Surface 182
7.3.1 Bouncing on a Horizontal Solid Surface 182
7.3.2 Bouncing on an Inclined Solid Surface 183
References 186
8 Miscellaneous Applications 191
Abstract 191
8.1 Behavior of a Bubble Attaching on a Sliding Gate 191
8.1.1 Introductory Remarks 191
8.1.2 Experiment 192
8.1.2.1 Experimental Apparatus and Procedure 192
8.1.2.2 Determination of Experimental Conditions 193
8.1.3 Classification of Bubble Attachment Patterns 194
8.1.3.1 Wetted Sliding Gate 194
8.1.3.2 Poorly Wetted Sliding Gate 195
8.1.4 Applicability of the Presently Obtained Findings to Real Immersion Nozzle 197
8.1.5 Summary 199
8.2 PIV Measurement on Inner Flow of a Water Droplet Dripping from a Nozzle 199
8.2.1 Introductory Remarks 199
8.2.2 Experiment 200
8.2.2.1 Relationship Between Diameter of Droplet and Nozzle Diameter 200
8.2.2.2 Flow Pattern in a Liquid Droplet 201
8.2.3 Experimental Results 203
8.2.3.1 Effect of the Wettability of Nozzle Edge on the Formation of Water Droplet 203
8.2.3.2 Flow Pattern in Water Droplet 205
8.2.4 Summary 207
8.3 Clean Steel Production Through Wettability Effect 208
8.3.1 Introductory Remarks 208
8.3.2 Removal of Small Bubbles Contained in Molten Metal Through Wettability Effect 209
8.3.3 Summary 209
References 212
Appendix A 215
Dimensionless Numbers 215
Dimensionless Numbers 216
Appendix B 216
Outline placeholder 1
Physical Properties of Gases and Liquids 216