Iguchi / Ilegbusi Modeling Multiphase Materials Processes

Gas-Liquid Systems
1. Auflage 2010
ISBN: 978-1-4419-7479-2
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 413 Seiten

Modeling Multiphase Materials Processes: Gas-Liquid Systems describes the methodology and application of physical and mathematical modeling to multi-phase flow phenomena in materials processing. The book focuses on systems involving gas-liquid interaction, the most prevalent in current metallurgical processes. The performance characteristics of these processes are largely dependent on transport phenomena. This volume covers the inherent characteristics that complicate the modeling of transport phenomena in such systems, including complex multiphase structure, intense turbulence, opacity of fluid, high temperature, coupled heat and mass transfer, chemical reactions in some cases, and poor wettability of the reactor walls. Also discussed are: solutions based on experimental and numerical modeling of bubbling jet systems, recent advances in the modeling of nanoscale multi-phase phenomena and multiphase flows in micro-scale and nano-scale channels and reactors.Modeling Multiphase Materials Processes: Gas-Liquid Systems will prove a valuable reference for researchers and engineers working in mathematical modeling and materials processing.

Autoren/Hrsg.

Iguchi, Manabu

Ilegbusi, Olusegun J.

Inhaltsverzeichnis

1;Preface;6
2;Contents;8
3;1 Introduction;12
3.1;1.1 Introductory Remarks;12
3.2;1.2 Classification of Models;13
3.2.1;1.2.1 Physical Modeling;13
3.2.2;1.2.2 Mathematical Modeling;14
3.3;1.3 General Strategy for Modeling Two-Phase Phenomena;14
3.4;1.4 Basic Physical Situations of Relevance in Gas–Liquid Processes;15
3.4.1;1.4.1 Gas–Liquid Two-Phase Flows in Cylindrical Bath;15
3.4.1.1;1.4.1.1 Bubbling and Jetting;15
3.4.1.2;1.4.1.2 Characteristic Parameters;16
3.4.2;1.4.2 Gas–Liquid Two-Phase Flows in Pipes;21
3.4.2.1;1.4.2.1 Vertical Pipes;22
3.4.2.2;1.4.2.2 Horizontal Pipe;23
3.4.3;1.4.3 Dimensionless Parameters;24
3.4.3.1;1.4.3.1 Reynolds Number, Re;24
3.4.3.2;1.4.3.2 Froude Number, Fr;25
3.4.3.3;1.4.3.3 Weber Number, We;25
3.4.3.4;1.4.3.4 Mach Number, M;25
3.4.3.5;1.4.3.5 Strouhal Number, St;26
3.5;1.5 Closing Remarks;26
3.6;References;26
4;2 Turbulence Structure of Two-Phase Jets;29
4.1;2.1 Mean Flow Characteristics;29
4.1.1;2.1.1 Introduction;29
4.1.2;2.1.2 Experiment;30
4.1.2.1;2.1.2.1 Bubble characteristics;30
4.1.2.2;2.1.2.2 Liquid Flow Characteristics;32
4.1.3;2.1.3 Experimental Results;33
4.1.3.1;2.1.3.1 Bubble Characteristics;33
4.1.3.2;2.1.3.2 Liquid Flow Characteristics;39
4.2;2.2 Conditional Sampling;43
4.2.1;2.2.1 Introductory Remarks;43
4.2.2;2.2.2 Experimental Apparatus and Procedure;44
4.2.3;2.2.3 Shape and Size of Helium Bubble;44
4.2.4;2.2.4 Four-Quadrant Classification Method;45
4.2.5;2.2.5 Experimental Results Based on Four-Quadrant Classification Method;46
4.3;2.3 Summary;50
4.3.1;2.3.1 Mean Flow Characteristics;50
4.3.1.1;2.3.1.1 Bubble Characteristics;50
4.3.1.2;2.3.1.2 Liquid Flow Characteristics;50
4.3.2;2.3.2 Conditional Sampling;51
4.4;References;52
5;3 The Coanda Effect;54
5.1;3.1 General Features;54
5.1.1;3.1.1 Overview;54
5.1.2;3.1.2 Mechanism of Coanda Effect;55
5.2;3.2 Wall Interaction in Metallurgical Reactor;56
5.2.1;3.2.1 Bubble Characteristics;56
5.2.1.1;3.2.1.1 Experimental Apparatus and Procedure;56
5.2.1.2;3.2.1.2 Experimental Results;58
5.2.1.3;3.2.1.3 Summary on Bubble Characteristics;68
5.2.2;3.2.2 Liquid Flow Characteristics;69
5.2.2.1;3.2.2.1 Experimental Apparatus and Procedure;69
5.2.2.2;3.2.2.2 Experimental Results;70
5.2.2.3;3.2.2.3 Summary of Liquid Flow Characteristics;78
5.3;3.3 Interaction Between Two Bubbling Jets;78
5.3.1;3.3.1 Critical Condition for Merging of Two Bubbling Jets;78
5.3.1.1;3.3.1.1 Experimental Apparatus and Procedure;78
5.3.1.2;3.3.1.2 Experimental Results;80
5.3.2;3.3.2 Merging Length of Two Bubbling Jets;82
5.3.2.1;3.3.2.1 Experimental Apparatus and Procedure;82
5.3.2.2;3.3.2.2 Experimental Results;82
5.3.2.3;3.3.2.3 Summary;86
5.3.3;3.3.3 Bubble Characteristics;86
5.3.3.1;3.3.3.1 Experimental Apparatus and Procedure;87
5.3.3.2;3.3.3.2 Experimental Results;87
5.3.3.3;3.3.3.3 Summary of Bubble Characteristics;93
5.3.4;3.3.4 Liquid Flow Characteristics;94
5.3.4.1;3.3.4.1 Experimental Apparatus and Procedure;94
5.3.4.2;3.3.4.2 Experimental Results;94
5.3.4.3;3.3.4.3 Summary of Liquid Flow Characteristics;98
5.3.5;3.3.5 Mixing Time;99
5.4;References;100
6;4 Interfacial Phenomena;103
6.1;4.1 Single Bubble on Flat Plate;103
6.1.1;4.1.1 Overview;103
6.1.2;4.1.2 Experimental Apparatus and Procedure;104
6.1.3;4.1.3 Experimental Results;106
6.1.3.1;4.1.3.1 Bubble Shape Using Potential Method;106
6.1.3.2;4.1.3.2 Bubble Volume at Incipient Detachment Using Energy and Force Balance;108
6.1.3.3;4.1.3.3 Bubble Shape and Size and Critical Volume Using Laplace and Potential Methods;110
6.1.3.4;4.1.3.4 Measured and Predicted Aspect Ratio and Critical Bubble Volume;113
6.1.4;4.1.4 Summary;114
6.2;4.2 Bubbling Jet Along Vertical Flat Plate;115
6.2.1;4.2.1 Bubble Characteristics;115
6.2.1.1;4.2.1.1 Overview;115
6.2.1.2;4.2.1.2 Experimental Apparatus and Procedure;117
6.2.1.3;4.2.1.3 Experimental Results;119
6.2.1.4;4.2.1.4 Summary;130
6.2.2;4.2.2 Liquid Flow Characteristics;131
6.2.2.1;4.2.2.1 Experimental Apparatus and Procedure;131
6.2.2.2;4.2.2.2 Results;132
6.2.2.3;4.2.2.3 Summary;140
6.3;4.3 Bubble Shape and Size;140
6.3.1;4.3.1 Experimental Apparatus and Procedure;143
6.3.2;4.3.2 Experimental Results;145
6.3.2.1;4.3.2.1 Bubble Attachment to Flat Plate;145
6.3.2.2;4.3.2.2 Bubble Collision with Flat Plate;148
6.3.2.3;4.3.2.3 Summary;154
6.4;4.4 Bubble Removal from Molten Metal;154
6.4.1;4.4.1 Experimental Apparatus and Procedure;154
6.4.2;4.4.2 Experimental Results;156
6.4.2.1;4.4.2.1 Behavior of Bubbling Jet Approaching Horizontal Cylinder;156
6.4.2.2;4.4.2.2 Behavior of Bubbles on Cylinder Surface;160
6.4.2.3;4.4.2.3 Stem Diameter and Stem Height of Trapped Bubble;161
6.4.2.4;4.4.2.4 Summary;165
6.5;4.5 Flow Distribution in Vertical Pipes;165
6.5.1;4.5.1 Experimental Apparatus and Procedure;166
6.5.2;4.5.2 Experimental Results;167
6.5.2.1;4.5.2.1 Flow Distribution;167
6.5.2.2;4.5.2.2 Bubbly Flow–Slug Flow Regime Boundary;169
6.5.2.3;4.5.2.3 Summary;171
6.5.3;4.5.3 Bubble Velocity and Size;172
6.5.3.1;4.5.3.1 Experimental Apparatus and Procedure;172
6.5.3.2;4.5.3.2 Experimental Results;172
6.5.3.3;4.5.3.3 Summary;179
6.6;References;180
7;5 Swirling Flow and Mixing;184
7.1;5.1 Rotary Sloshing of Liquid in Cylindrical Vessel;184
7.1.1;5.1.1 Linear Theory;184
7.1.2;5.1.2 Nonlinear Theory;185
7.1.3;5.1.3 Summary;186
7.2;5.2 Swirl Motion of Bubbling Jet;188
7.2.1;5.2.1 General Features;188
7.2.1.1;5.2.1.1 Classification of Swirl Motion;188
7.2.1.2;5.2.1.2 The First Kind of Swirl Motion;190
7.2.1.3;5.2.1.3 The Second Kind of Swirl Motion;195
7.2.1.4;5.2.1.4 Summary;199
7.2.2;5.2.2 Operation Under Reduced Surface Pressure;200
7.2.2.1;5.2.2.1 Experimental Apparatus and Procedure;201
7.2.2.2;5.2.2.2 Experimental Results and Discussion;202
7.2.2.3;5.2.2.3 Summary;209
7.2.3;5.2.3 Mixing Time;209
7.2.3.1;5.2.3.1 Experimental Apparatus and Procedure;210
7.2.3.2;5.2.3.2 Experimental Results;211
7.2.3.3;5.2.3.3 Summary;217
7.2.4;5.2.4 Effect of Top Slag;217
7.2.4.1;5.2.4.1 Experimental Apparatus and Procedure;218
7.2.4.2;5.2.4.2 Experimental Results;218
7.2.4.3;5.2.4.3 Summary;223
7.2.5;5.2.5 Effect of Offset Gas Injection;224
7.2.6;5.2.6 Effect of Dual Jet Sources;225
7.3;References;227
8;6 Slag–Metal Interaction;230
8.1;6.1 Shape and Size of Entrained Metal Layer;230
8.1.1;6.1.1 Experiment;231
8.1.2;6.1.2 Experimental Results;235
8.1.2.1;6.1.2.1 Total Holdup Distribution in the Slag Layer;235
8.1.2.2;6.1.2.2 Horizontal Distribution of Elevated Molten Metal Holdup;236
8.1.2.3;6.1.2.3 Height and Volume of Molten Metal in the Elevated Region;239
8.1.2.4;6.1.2.4 Accumulated Molten Metal Droplets;245
8.2;6.2 Characteristics of Metal Droplets;247
8.2.1;6.2.1 Experiment;248
8.2.2;6.2.2 Experimental Results;249
8.2.2.1;6.2.2.1 Mechanism of Metal Droplet Generation;249
8.2.2.2;6.2.2.2 Total Volume of Accumulated Molten Metal Droplets at Steady State, V;251
8.2.2.3;6.2.2.3 Birth Rate of Molten Metal Droplets;254
8.2.2.4;6.2.2.4 Lifetime of Molten Metal Droplet, ;257
8.2.2.5;6.2.2.5 Death Rate of Molten Metal Droplets After Stoppageof Gas Injection;258
8.3;6.3 Summary;260
8.3.1;6.3.1 Shape and Size of Entrained Metal Layer;260
8.3.2;6.3.2 Characteristics of Metal Droplets;261
8.4;References;261
9;7 Surface Flow Control;263
9.1;7.1 Overview;263
9.2;7.2 Experiment;264
9.2.1;7.2.1 Experimental Apparatus and Procedure;264
9.2.2;7.2.2 Boundary Conditions on Bath Surface;265
9.2.3;7.2.3 Data Processing;265
9.3;7.3 Experimental Results;266
9.3.1;7.3.1 Mixing Time;266
9.3.2;7.3.2 Fluid Flow Phenomena;267
9.3.2.1;7.3.2.1 Mean Velocity Components;267
9.3.2.2;7.3.2.2 Root-Mean-Square Turbulence Components and Reynolds Shear Stress;271
9.4;7.4 Conclusions;274
9.5;References;276
10;8 Two-Phase Flow in Continuous Casting;277
10.1;8.1 Flow Characteristics;277
10.1.1;8.1.1 Overview;277
10.1.2;8.1.2 Experiment;278
10.1.2.1;8.1.2.1 Experimental Apparatus;278
10.1.2.2;8.1.2.2 Dimensional Analysis;278
10.1.2.3;8.1.2.3 Experimental Procedure;280
10.1.3;8.1.3 Experimental Results;281
10.1.3.1;8.1.3.1 Dispersion of Bubbles and Mean Bubble Diameter;281
10.1.3.2;8.1.3.2 Mean Velocities and Root-Mean-Square Turbulence Components;281
10.1.3.3;8.1.3.3 Vertical Distribution of Axial Mean Velocity;283
10.1.3.4;8.1.3.4 Vertical Distribution of Root-Mean-Square Turbulence Components;283
10.1.3.5;8.1.3.5 Empirical Relations for Mean Velocity Components;285
10.1.4;8.1.4 Summary;291
10.2;8.2 Mold Powder Entrapment;292
10.2.1;8.2.1 Overview;292
10.2.2;8.2.2 Experimental Apparatus and Procedure;294
10.2.3;8.2.3 Some Aspects of Kelvin–Helmholtz Instability;296
10.2.3.1;8.2.3.1 Critical Velocity Difference for the Onset of Kelvin–Helmholtz Instability;296
10.2.3.2;8.2.3.2 Wavelength and Amplitude of Instability Wave;297
10.2.4;8.2.4 Experimental Results;298
10.2.4.1;8.2.4.1 Visualized Flow Field and Velocity Vectors;298
10.2.4.2;8.2.4.2 Critical Velocity Difference for the Onset of KHI;298
10.2.4.3;8.2.4.3 Comparison of Measured and Calculated Critical Salt Water Flow Velocity;299
10.2.4.4;8.2.4.4 Wavelength and Amplitude of KHI;304
10.2.4.5;8.2.4.5 KHI-Induced Mold Powder Entrapment in Continuous Casting Mold;305
10.2.5;8.2.5 Summary;306
10.3;References;306
11;9 Modeling Gas–Liquid Flow in Metallurgical Operations;309
11.1;9.1 Overview;309
11.2;9.2 Review of Modeling Methods;309
11.3;9.3 Mathematical Models;314
11.3.1;9.3.1 Quasi-Single-Fluid (Momentum Balance) Models;315
11.3.1.1;9.3.1.1 Two-Phase Zone Modeling;316
11.3.1.2;9.3.1.2 Turbulence Modeling;320
11.3.2;9.3.2 Two-Fluid Model;325
11.3.2.1;9.3.2.1 Eulerian–Eulerian Model;325
11.3.2.2;9.3.2.2 Eulerian–Lagrangian model;328
11.3.3;9.3.3 Mathematical Models Based on Energy Balance;333
11.4;9.4 Boundary Conditions;335
11.5;9.5 Numerical Solution;337
11.6;References;338
12;10 Numerical Modeling of Multiphase Flows in Materials Processing;342
12.1;10.1 Overview;342
12.2;10.2 Control Volume-Based Finite Difference Method;343
12.2.1;10.2.1 Continuum Mixture Model;343
12.2.2;10.2.2 Two-Fluid Models;350
12.3;10.3 The Finite Element Method;355
12.4;10.4 Multi-domain (Two-Region) Methods;363
12.5;10.5 Boundary Conditions;368
12.5.1;10.5.1 Boundary Conditions in Multiphase Models;371
12.5.2;10.5.2 Boundary Conditions for Multi-region Method;372
12.6;References;373
13;11 Review of Nanoscale and Microscale Phenomena in Materials Processing;379
13.1;11.1 Introduction;379
13.1.1;11.1.1 Fundamentals;379
13.1.2;11.1.2 Applications;380
13.2;11.2 Definitions and Generation Method of Nanoscale and Microscale;380
13.2.1;11.2.1 Bubbles;380
13.2.1.1;11.2.1.1 Nanobubble and Microbubble;380
13.2.2;11.2.2 Generation Method;381
13.3;11.3 Removal of Gas from Gas–Liquid Mixture;382
13.4;11.4 Flow Pattern of Gas–Liquid Two-Phase Flow in Microchannels;383
13.5;11.5 Flow Characteristics in Microchannels;386
13.6;11.6 Heat Transfer in Microchannels;386
13.7;11.7 Numerical Simulation of Transport Phenomena;387
13.8;11.8 Mixing in Microchannels and Microreactors;387
13.9;11.9 Measurement Method;387
13.10;11.10 Enhancement of Gas Dissolution Rate;387
13.11;11.11 Microfluidic Devices;388
13.12;11.12 Fuel Cell;388
13.13;11.13 Closing Remarks;388
13.14;References;388
14;Appendix 1;392
15;Appendix 2;396
16;Index;414