Shrimpton Charge Injection Systems

Physical Principles, Experimental and Theoretical Work
1. Auflage 2009
ISBN: 978-3-642-00294-6
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 196 Seiten

Reihe: Heat and Mass Transfer

C Specific heat at constant pressure p D Displacement field D Diffusion coefficient d D Orifice diameter E Electric field E Electron charge F Force G Acceleration due to gravity I Current J Current flux K Conductivity k Boltzmann constant B L Atomizer geometry: length from electrode tip to orifice plane i L Atomizer geometry : length of orifice channel o P Polarization Q Flow rate/Heat flux Q Charge r Atomizer geometry : electrode tip radius p T Time T Temperature U Velocity V Voltage W Energy X Distance Nomenclature (Greek) Thermal expansion coefficient ? Permittivity ? Permutation operator ? ijk Ion mobility ? VI Nomenclature Debye length ? D ? Dynamic viscosity ? Mass density Surface tension ? T Electrical conductivity ? ? Timescale ? Vorticity Nomenclature (Subscripts) Reference state ? o Cartesian tensor notation ? ijk Volume density (? per unit volume) ? v Surface density (? per unit area) ? s Linear density (? per unit length) ? l 'critical' state ? c Bulk mean injection ? inj Nomenclature (Superscripts) Time or ensemble averaged ? Contents Contents 1 Introduction................................................................... 1 1.1 Introduction and Scope.................................................. 1 1.2 Organization.............................................................. 3 2 Electrostatics, Electrohydrodynamic Flow, Coupling and Instability.................................................................. 5 2.1 Electrostatics.............................................................. 5 2.1.1 The Coulomb Force............................................. 5 2.1.2 Permittivity...................................................... 6 2.1.3 Conductors, Insulators, Dielectrics and Polarization........ 6 2.1.4 Gauss's Law...................................................... 8 2.2 Mobility and Charge Transport........................................ 10 2.2.1 Introduction...................................................... 10

Autoren/Hrsg.

Shrimpton, John

Shrimpton, J.S.

Inhaltsverzeichnis

1;Nomenclature;5
2;Contents;7
3;Chapter 1 Introduction;11
3.1;Introduction and Scope;11
3.2;Organization;13
4;Chapter 2 Electrostatics, Electrohydrodynamic Flow, Coupling and Instability;15
4.1;Electrostatics;15
4.1.1;{\it The Coulomb Force};15
4.1.2;{\it Permittivity};16
4.1.3;{\it Conductors, Insulators, Dielectrics and Polarization};16
4.1.4;{\it Gauss’s Law};18
4.2;Mobility and Charge Transport;20
4.2.1;{\it Introduction};20
4.2.2;{\it Convective Transport by Fluid Motion};20
4.2.3;{\it Mobility and the Drift Term};20
4.2.4;{\it Diffusion and the Debye Length};21
4.2.5;{\it Charge Conservation};22
4.3;Momentum and Energy;23
4.3.1;{\it Introduction};23
4.3.2;{\it Electrical Forces};23
4.3.3;{\it Momentum Conservation};24
4.3.4;{\it Energy Conservation};24
4.4;Electrical Timescales;25
4.4.1;{\it Introduction};25
4.4.2;{\it Ohmic-Charge Relaxation};25
4.4.3;{\it Space-Charge Relaxation};25
4.4.4;{\it Ionic Diffusion Timescale};26
4.4.5;{\it Ionic Transit Timescale};26
4.4.6;{\it Electro-viscous Timescale};27
4.4.7;{\it Electro-inertial Timescale};27
4.5;Non-dimensional Transport Equations;27
4.5.1;{\it Introduction};27
4.5.2;{\it Momentum Conservation: Free Flow};28
4.5.3;{\it Momentum Conservation: Forced Flow};29
4.5.4;{\it Non-dimensional Parameters};29
4.6;Electrohydrodynamics;31
4.6.1;{\it Introduction};31
4.6.2;{\it Fundamentals};32
4.6.3;{\it Instability};32
4.6.4;{\it Plumes};36
4.6.5;{\it Transition to Turbulence};39
4.7;Electrohydrodynamic Turbulence in a Propagating Flow Front;40
4.7.1;{\it EHD Vorticity};40
4.7.2;{\it EHD RANS in a Propagating Flow Front};41
4.7.3;{\it Transient Turbulence};42
4.7.4;{\it AC Turbulence};43
4.7.5;{\it Current and Voltage};43
4.8;Chapter Summary;45
5;Chapter 3 Charge Injection into a Quiescent Dielectric Liquid;46
5.1;Charge and Field Distribution;46
5.1.1;{\it Field Emission and Ionization};46
5.1.2;{\it Electrochemical};47
5.1.3;{\it Ohmic Conduction};48
5.1.4;{\it Space-Charge};48
5.1.5;{\it Point Sharpness};48
5.1.6;{\it Hyperbolic Field Expression};49
5.2;IV Characteristics of Point-Plane Systems;49
5.2.1;{\it Steady-State Behavior};49
5.2.2;{\it Current Instabilities};53
5.3;Vapor Bubble Creation and Pressure Dependence in Liquids;58
5.3.1;{\it Vapor Bubble Formation};58
5.3.2;{\it Vapor Bubble Growth: Pulsed Voltage Operation};60
5.3.3;{\it Vapor Bubble Growth: Constant Voltage};61
5.3.4;{\it Vapor Bubble Evolution};67
5.4;Chapter Summary;69
6;Chapter 4 Single Charged Drop Stability, Evaporation and Combustion;70
6.1;Maximum Spherical Drop Charge;70
6.2;Maximum Spheroidal Drop Charge;78
6.3;Spheroidal Deformation of Non-stationary Charged Drops;79
6.4;Models for Products of Charged Drop Disruption;81
6.5;Combustion of Single Drops;85
6.6;Summary;86
7;Chapter 5 Charge Injection Atomizers: Design and Electrical Performance;87
7.1;Overview: Electrostatic Atomization for Electrically Semi-conducting Liquids;87
7.2;Overview: Electrostatic Atomization for Electrically Insulating Liquids;89
7.3;Atomizer Construction;90
7.4;Nozzle Design;92
7.5;Rig Design;93
7.6;Liquids Used;94
7.7;Breakdown Limits and Typical Current-Voltage Response;95
7.7.1;{\it Sub-critical Breakdown};95
7.7.2;{\it Super-critical Breakdown};99
7.7.3;{\it Overview of the Breakdown Regimes};102
7.8;Total Current Versus Voltage: Observations;102
7.9;Total Current Versus Voltage: Comparison to Quiescent Fluid Data;104
7.10;Effect of Flow-Rate/Injection Velocity;108
7.11;Specific Charge Regimes;109
7.12;Specific Charge: Summary;114
7.13;Variation of Electrode Gap Ratio (L_{i}/d), L_{0}/d=2, d=500$\mu$m, Version 1 Design;115
7.14;Variation of d: Version 1 Design: Constant Q, L_{i}, L_{0}/d;118
7.15;Variation of Electrode Gap Ratio (L_{i}/d): Version 2 Design, d=500$\mu$m;120
7.16;Variation of Electrode Gap Ratio (L_{i}/d): Version 2 Design, d=250$\mu$m;122
7.17;Performance Evaluation: Version 1 and Version 2;124
7.18;Point-Plane Atomizer Design Modifications;125
7.19;Beyond the Point-Plane Atomizer Concept;129
7.19.1;{\it Single Hole Electrostatically Enhanced Pressure Swirl Atomizers};129
7.19.2;{\it Multi-hole Charge Injection Atomizers};130
7.19.3;{\it Pulsed Spray Charge Injection Atomizers};130
7.19.4;{\it Other Developments within Charge Injection Atomization};131
7.20;Chapter Summary;131
8;Chapter 6 Jet Instability and Primary Atomization;133
8.1;Measured Characteristics;133
8.2;Orifice Channel Space Charge Distribution Model;140
8.3;Chapter Summary;145
9;Chapter 7 Spray Characterization and Combustion;146
9.1;Spray Visualization and Prediction of Expansion Rate;146
9.2;Quantitative Spray Characteristics;153
9.3;Estimation of the Radial Profile of Spray Specific Charge;161
9.4;Models for Drop Diameter and Charge Distributions;167
9.4.1;{\it Energy Minimization Methods};167
9.4.2;{\it Spray Theory of Kelly};170
9.5;Spray Combustion;180
9.6;Summary;185
10;Chapter 8 Conclusions and Future Outlook;187
10.1;Conclusions;187
10.2;Future Outlook;189
11;References;191
12;Index;201