Droplets and Sprays (eBook)

Applications for Combustion and Propulsion

Saptarshi Basu, Avinash Kumar Agarwal, Achintya Mukhopadhyay, Chetankumar Patel (Herausgeber)

eBook Download: PDF

2017 | 1st ed. 2018
XIV, 430 Seiten
Springer Singapore (Verlag)
978-981-10-7449-3 (ISBN)

Infos

This book focuses on droplets and sprays relevant to combustion and propulsion applications. The book includes fundamental studies on the heating, evaporation and combustion of individual droplets and basic mechanisms of spray formation. The contents also extend to the latest analytical, numerical and experimental techniques for investigating the behavior of sprays in devices like combustion engines and gas turbines. In addition, the book explores several emerging areas like interactions between sprays and flames and the dynamic characteristics of spray combustion systems on the fundamental side, as well as the development of novel fuel injectors for specific devices on the application side. Given its breadth of coverage, the book will benefit researchers and professionals alike.

Prof. Saptarshi Basu is currently an Associate Professor at the Department of Mechanical Engineering, Indian Institute of Science, Bangalore. His current research interests include combustion instability, flame-vortex interaction, droplet-level transport, multiphase combustion, spray atomization and breakup, water transport characteristics in fuel cells and general areas of heat and mass transfer. Prof. Basu has published over 109 articles in different frontline journals, and is a recipient of the DST Swarnajayanti Fellowship from the Government of India in Engineering Sciences. He also received the K.N. Seetharamu Medal from the Indian Society of Heat and Mass Transfer for his contributions in multiphase transport. Prof. Basu is a member of the ASME, ISHMT and Combustion Institute. He is a Fellow of the Indian National Academy of Engineering. 

Prof. Avinash K Agarwal joined the IIT Kanpur, India in 2001. His areas of interest are IC engines, combustion, alternative fuels, conventional fuels, optical diagnostics, laser ignition, HCCI, emission and particulate control, and large bore engines. He has published 230+ international journal and conference papers. Prof. Agarwal is a Fellow of the SAE (2012), ASME (2013), ISEES (2015) and INAE (2015). He has received several awards such as the prestigious Shanti Swarup Bhatnagar Award 2016 in Engineering Sciences; Rajib Goyal Prize-2015; NASI-Reliance Industries Platinum Jubilee Award-2012; and INAE Silver Jubilee Young Engineer Award-2012. 

Prof. Achintya Mukhopadhyay is a Professor of Mechanical Engineering at Jadavpur University, Kolkata (Calcutta), India. He also served as Professor of Mechanical Engineering at the Indian Institute of Technology Madras, India. Prof. Mukhopadhyay's major research interests are chemically reacting flows, multiphase flow and heat transfer and microscale flow and heat transfer. His current research activities include droplet and spray combustion, structure and dynamics of partially premixed flames, nonlinear dynamics and chaos in combustion systems. Prof. Mukhopadhyay has authored over 250 research publications, including 94 international journal publications. Prof. Mukhopadhyay is a Fellow of the West Bengal Academy of Science and Technology and a life member of the Indian Society of Heat and Mass Transfer, Indian Section of the Combustion Institute, International Society for Energy, Environment and Sustainability and a member of the Society of Automotive Engineers (India). 

Dr. Chetankumar Patel is currently a Project Scientist at the Engine Research Laboratory, IIT Kanpur, India, where he also completed his PhD in 2016. He graduated from the Department of Mechanical Engineering, L.D. College of Engineering, Ahmedabad in 2002. He subsequently completed his Master's Degree in Mechanical Engineering with a specialization in IC Engines and Automobiles from the same institute in 2007. Dr. Patel taught Mechanical Engineering for 4 years in engineering institutes in India. His main areas of research include microscopic and macroscopic spray investigations, in-cylinder spray and combustion visualization, in-cylinder combustion investigations, emissions, noise and vibration investigations, and biofuels. He has published several peer-reviewed papers in high-impact journals.

Inhalt

Preface 6
Contents 9
Editors and Contributors 11
Multiphase Flow Fundamentals 15
1 Introduction to Droplets and Sprays: Applications for Combustion and Propulsion 16
Abstract 16
2 Towards Combined Deterministic and Statistical Approaches to Modeling Dispersed Multiphase Flows 20
2.1 Introduction 21
2.1.1 Fully Resolved (FR) Approach 22
2.1.2 Point-Particle (PP) Approach 23
2.1.3 Euler--Lagrange Interphase Coupling Models 25
2.2 Single-Particle Drag 28
2.2.1 Reynolds Number Effects 30
2.2.2 Turbulence Effects 32
2.3 Beyond Single-Particle DNS 35
2.3.1 FR-DNS of Random Arrays 36
2.3.2 Computational Drag Laws 36
2.3.3 Developing LE Particle Force Models from FR-DNS 38
2.4 Deterministic Coupling Models 40
2.4.1 Neighbors Matter 41
2.4.2 PIEP Model 43
2.4.3 PIEP Results 44
2.5 Stochastic Models 45
2.5.1 Particle Dispersion and Turbulence Modulation in Dilute Turbulent Flow 45
2.5.2 Neighbor Effects in Non-dilute Gas--Solid Flow with Mean Slip 48
2.6 Outlook and Challenges 49
References 51
Droplet Evaporation and Combustion 56
3 Modelling of Droplet Heating and Evaporation 57
3.1 Introduction 57
3.2 Heating of Non-evaporating Droplets 58
3.3 Hydrodynamic Models (Mono-component Droplet Heating and Evaporation) 62
3.4 Hydrodynamic Models (Multi-component Droplet Heating and Evaporation) 68
3.5 Kinetic and Molecular Dynamics Models 78
References 81
4 Combustion of Multi-component Fuel Droplets 88
4.1 Introduction and Background 88
4.2 Numerical Studies on Droplet Evaporation and Combustion 90
4.3 Experimental Studies on Multi-component Droplet Combustion 102
4.3.1 Review of Experimental Approaches in Droplet Combustion 103
4.3.2 Disruptive Phenomena in Multi-component Miscible Droplets 105
4.3.3 Disruptive Phenomena in Emulsion Droplets 111
4.4 Introduction to Combustion of Nanofuel Droplet 115
4.5 Conclusion 121
References 121
Atomization Principles and Injection Strategies 126
5 On Primary Atomization in Propulsive Device Fuel Injectors—A Short Review 127
Abstract 127
5.1 Introduction 127
5.2 Primary Atomization 128
5.3 Primary Atomization in Pressure-Atomizing Nozzles 131
5.3.1 Pressure Jet Atomizer 131
5.3.2 Experimental Approaches in Primary Atomization 132
5.3.3 Pressure Swirl Atomizer 138
5.4 Primary Atomization in Twin-Fluid Atomizer 140
5.4.1 Plain Coaxial Air-Assisted Atomizer 141
5.4.2 Swirl Coaxial Air-Assist Atomization 144
5.5 Summary and Conclusions 148
Acknowledgements 148
References 148
6 A Comprehensive Model for Estimation of Spray Characteristics 151
Abstract 151
6.1 Introduction 152
6.2 Design of Atomizer 154
6.3 Model Description 156
6.3.1 Internal Hydrodynamics: Computational Fluid Dynamics 156
6.3.2 Linear Stability Analysis 161
6.3.3 Comparison with In-house Experiments 164
6.3.4 Maximum Entropy Formulation 168
6.4 Constraint Conditions 169
6.5 Conclusions 173
References 173
7 Modeling of Flash Boiling Phenomenon in Internal and Near-Nozzle Flow of Fuel Injectors 176
7.1 Introduction 177
7.2 Model Formulation 179
7.2.1 Nozzle Geometry and Computational Domain 180
7.2.2 Governing Equations 182
7.3 Results and Discussions 184
7.3.1 Boundary and Operating Conditions 184
7.3.2 Turbulence Models 184
7.3.3 Blended Fuels 186
7.4 Summary and Concluding Remarks 189
References 189
8 Novel Fuel Injection Systems for High-Speed Combustors 191
Abstract 191
8.1 Introduction 191
8.2 Fuel Injector Needs and Challenges in High-Speed Combustors 192
8.3 Fuel Injection System in High-Speed Combustors 194
8.3.1 Transverse Fuel Injection System 194
8.3.2 Parallel Injection Systems 195
8.4 Conventional Standalone Atomizers 198
8.4.1 Coaxial Atomizers 198
8.4.2 Flash-Boiling Atomizer 200
8.4.3 Effervescent Atomizer 203
8.4.4 Working Principle 204
8.4.5 Electrospray 206
8.4.6 Ultrasonic Atomizer 208
8.5 Hybrid Atomizers 209
8.5.1 Why Hybrid Atomizer? 209
8.5.2 Effervescent Cum Air-Assist Atomizer 210
8.5.2.1 Design 211
8.5.2.2 Experimental Conditions and Procedure 211
8.5.2.3 Working Principle 213
8.5.3 Size Distribution 215
8.5.4 Influence of Design and Operational Parameters 216
8.5.5 Combined Electrostatic and Pressure Jet Atomizer 216
8.5.6 Flash-Boiling Cum Pressure Jet Atomizer 218
8.5.7 Externally Forced Sprays 220
8.6 Summary and Conclusions 221
Acknowledgements 221
References 221
9 Experimental Investigation of Spray Characteristics of Kerosene, Ethanol, and Ethanol-Blended Kerosene Using a Gas Turbine Hybrid Atomizer 225
Abstract 225
9.1 Introduction 226
9.2 Equipment and Method 231
9.2.1 Atomizer 231
9.2.2 Blend 234
9.2.3 Experimental Setup and Image Capturing Technique 236
9.3 Results and Discussion 237
9.3.1 Breakup Phases 240
9.3.2 Macroscopic Spray Characteristics 248
9.4 Conclusions 251
References 252
10 Two-Phase Characterization for Turbulent Dispersion of Sprays: A Review of Optical Techniques 254
10.1 Introduction 255
10.2 Challenges for Two-Phase Measurements in Sprays 259
10.2.1 Droplet Measurement Techniques 259
10.2.2 Two-Phase Measurement Techniques 259
10.3 Planar Techniques for Two-Phase Measurements in Sprays 261
10.3.1 Dense Spray Measurements 263
10.3.2 Dilute Spray Measurements 268
10.4 Summary and Outlook 275
References 276
Turbulent Spray Combustion 281
11 Turbulent Spray Combustion 282
Abstract 282
11.1 Introduction 283
11.2 Turbulent Combustion Characteristics 287
11.2.1 Optical Diagnostics and Analysis 287
11.2.2 Reacting Spray: Fundamental and Characteristics 293
11.2.3 Partially Premixed Combustion 302
11.3 Numerical Approaches 305
11.3.1 RANS and LES Modeling 307
11.3.2 Direct Numerical Simulation (DNS) 310
11.4 Further Discussion 311
11.5 Summary 312
11.6 Disclaimer and Funding Acknowledgement 312
References 312
12 Modelling of Variance and Co-variance in Turbulent Flame–Droplet Interaction: A Direct Numerical Simulation Analysis 318
Abstract 318
12.1 Introduction 323
12.2 Mathematical Formulation of Flame–Droplet Interaction 325
12.2.1 Fuel Mass Fraction Variance /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{{/prime /prime }/thinspace 2}} }} Transport Equation 330
12.2.2 Mixture Fraction Variance /widetilde{{{/varvec /xi}^{{{/prime /prime }/thinspace 2}} }} Transport Equation 330
12.2.3 Co-variance /widetilde{{{/varvec Y}_{{/varvec F}}^{{{/varvec ''}}}{/varvec /xi}^{{/prime /prime }} }} Transport Equation 331
12.3 Attributes of DNS Data and Numerical Implementation 332
12.4 Result and Discussion 334
12.4.1 Flame Behaviour 334
12.4.2 Modelling of Fuel Mass Fraction Variance /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{{/prime /prime }/thinspace 2}} }} 336
12.4.2.1 Algebraic Modelling of Fuel Mass Fraction Variance /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{{/prime /prime }/thinspace 2}} }} 336
12.4.2.2 Modelled Transport Equation for /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{{/prime /prime }/thinspace 2}} }} 340
Statistical Behaviour of the Terms of /widetilde{{{/hbox{Y}}_{{/rm F}}^{{{/prime /prime }/thinspace 2}} }} Transport Equation 341
Modelling of {/hbox{T}}_{{{{/rm Y}}1}} 342
Modelling of {/hbox{T}}_{{{{/bf Y}}3}} 344
Modelling of {/hbox{T}}_{{{{/bf Y}}4}} 346
Modelling of {{D}}_{{{{/bf Y}}2}} 346
12.4.3 Modelling of Mixture Fraction Variance /widetilde{{{{/varvec /upxi}}^{{{/prime /prime }/thinspace 2}} }} 349
12.4.3.1 Modelled Transport Equation for /widetilde{{{{/varvec /upxi}}^{{{/prime /prime }/thinspace 2}} }} 349
Statistical Behaviour of the Terms /widetilde{{{{/upxi}}^{{{/prime /prime }/thinspace 2}} }} Transport Equation 349
Modelling of {/hbox{T}}_{{{{/varvec /upxi}}1}} 351
Modelling of {/hbox{T}}_{{{{/varvec /upxi}}3}} 354
Modelling of {/hbox{T}}_{{{{/varvec /upxi}}4}} 354
Modelling of {/hbox{D}}_{{{{/varvec /upxi}}2}} 357
12.4.4 Modelling of Co-variance of Fuel Mass Fraction and Mixture Fraction /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{/prime /prime }} {{/varvec /upxi}}^{{/prime /prime }} }} 357
12.4.4.1 Algebraic Modelling of Co-variance /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{/prime /prime }} {{/varvec /upxi}}^{{/prime /prime }} }} 357
12.4.4.2 Modelled Transport Equation for /widetilde{{{{/bf Y}}_{{{/bf F}}}^{{/prime /prime }} {{/varvec /upxi}}^{{/prime /prime }} }} 360
Statistical Behaviour of the Terms of the /widetilde{{{/hbox{Y}}_{{{/rm F}}}^{{/prime /prime }} {{/varvec /upxi}}^{{/prime /prime }} }} Transport Equation 360
Modelling of {/hbox{T}}_{{{{/bf Y/xi }}1}} 361
Modelling of {/hbox{T}}_{{{{/rm Y}/xi }4}} 363
Modelling of {/hbox{T}}_{{{{/rm Y}/xi }5}} 364
Modelling of {/hbox{D}}_{{{{/rm Y}/xi }2}} 364
12.5 Concluding Remarks 368
Acknowledgements 369
References 369
Droplet and Spray Dynamics 372
13 Dynamics of Droplet Break-Up 373
13.1 Introduction and Background 373
13.2 Different Aspects of Droplet Break-Up 375
13.2.1 Free-Falling Droplets 375
13.2.1.1 Different Break-Up Mechanisms 375
13.2.1.2 Influence of External Flow Field 377
13.2.2 Sessile Droplets 379
13.2.2.1 Influence of Vibrating Surface 379
13.2.2.2 Scaling Analysis 382
13.2.3 Acoustically Levitated Droplets 387
13.2.3.1 Influence of Acoustic Pressure 387
13.2.3.2 Combined Effect of Acoustic Pressure and External Heating 389
Pure Fluid Droplets 389
Bicomponent Fuel Droplets 391
Droplets with Lower Concentration of the Highly Volatile Component 392
Droplets with Higher Concentration of the Highly Volatile Component 394
Functionalized Droplets 396
13.2.4 Droplet Impact on Liquid Pools 398
13.3 Conclusions 402
References 403
14 Intermittency: A State that Precedes Thermoacoustic Instability 406
14.1 Introduction 407
14.2 Tools from Nonlinear Dynamics 412
14.2.1 Phase Space Reconstruction 412
14.2.2 Recurrence Plots and Quantification Analysis 414
14.3 Experimental Set-up 416
14.4 Results and Discussion 418
14.4.1 Intermittency Route to Thermoacoustic Instability 418
14.4.2 Qualitative and Quantitative Analysis of Intermittency Route 421
14.4.3 Detection of Type of Intermittency 426
14.5 Conclusion 430
References 431

Produkt-Details

• Erscheint lt. Verlag: 11.12.2017
• Reihe/Serie: Energy, Environment, and Sustainability
• Reihe/Serie: Energy, Environment, and Sustainability
• Zusatzinfo: XIV, 430 p. 221 illus., 153 illus. in color.
• Verlagsort: Singapore
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Atomization • Droplet and Spray Combustion • Fuel Injectors • Spray Flame Dynamics • Spray-Flame Interaction
• ISBN-10: 981-10-7449-6 / 9811074496
• ISBN-13: 978-981-10-7449-3 / 9789811074493