Modeling and Simulation of Turbulent Combustion (eBook)

Dr. Santanu De has been an Assistant Professor at the Department of Mechanical Engineering, IIT Kanpur since December 2014. He received a Bachelor of Engineering degree from the North Bengal University, Darjeeling, West Bengal in 2002, and an M.Tech. from the IIT Kanpur in 2004, both in Mechanical Engineering. He received his Ph.D. in Aerospace Engineering from the Indian Institute of Science, Bangalore in 2012. Prior to joining the IIT Kanpur, he served two years at Michigan Technological University, Michigan, USA as a postdoctoral research associate, and one year at the Institute of Combustion Technology (ITV), University of Stuttgart, Germany. He also worked as a scientist at the Liquid Propulsion Systems Center, Indian Space Research Organization, Thiruvananthapuram, from 2004 to 2005. His primary areas of research are numerical modeling of turbulent combustion, spray atomization and combustion, coal gasification and combustion. Prof. Avinash K. Agarwal joined the IIT Kanpur 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 in Engineering Sciences-2016; Rajib Goyal prize-2015; NASI-Reliance Industries Platinum Jubilee Award-2012; and INAE Silver Jubilee Young Engineer Award-2012. Dr. Swetaprovo Chaudhuri has been an Assistant Professor at the Department of Aerospace Engineering, Indian Institute of Science, Bangalore, India since June 2013. Prior to this appointment he was a member of research staff at Princeton University, New Jersey, USA. He received his Ph.D. from the University of Connecticut, USA in 2010 and his B.E. from Jadavpur University, Kolkata (Calcutta), India in 2006. His research interests include fundamental and applied aspects of turbulent combustion, propulsion and functional droplets. He has authored/co-authored more than 70 articles disseminated through international journals and conference proceedings. Recently, he was selected as the recipient of the Young Scientist Medal by the Indian National Science Academy, New Delhi, India and as an Associate of the Indian Academy of Sciences, Bangalore, India. His earlier contributions have been recognized by the American Society of Mechanical Engineers, New York, USA and by the University of Connecticut.  Dr. Swarnendu Sen is a Professor at the Department of Mechanical Engineering, Jadavpur University, Kolkata, India, where he has been teaching since November 1989. He earned his Bachelor and Master’s in Mechanical Engineering as well as a Ph.D. (Engineering) from Jadavpur University. He worked at the University of Illinois at Chicago, Illinois, USA and Virginia Tech, Virginia, USA as a Visiting Research Scholar. He has also worked at the Technical University of Munich, Germany as a DAAD Fellow. His research interests include fundamental and applied aspects of reacting and multiphase flows, heat transfer augmentation and carbon nano-structure synthesis. He has authored/co-authored more than 200 articles disseminated through top journals and conference proceedings.

Foreword 6
Preface 8
Contents 11
Editors and Contributors 14
Fundamentals, Methodology and Architecture of Turbulent Combustion Computations 18
1 Mechanics and Modelling of Turbulence–Combustion Interaction 19
Abstract 19
1.1 Introduction 21
1.2 Fundamentals of Turbulence and Turbulence–Premixed Flame Interaction 22
1.3 Simulation of Reactive Flows 29
1.3.1 Chemical Reaction Rates 32
1.4 Reynolds-Averaged Navier–Stokes of Reactive Flows 33
1.4.1 Averaging and Averaged Equations 33
1.4.2 Turbulence Model 35
1.4.3 Transport of Non-reactive Scalars 37
1.4.4 Transport of Reactive Scalars 38
1.5 Large Eddy Simulation of Reactive Flows 39
1.5.1 Filtering Operation 40
1.5.2 Filtered Navier–Stokes Equations 41
1.5.2.1 Smagorinsky Model 41
1.5.2.2 Dynamic Smagorinsky Model 42
1.5.3 Transport Equations for Filtered Reactive Scalars 43
1.5.4 Subgrid-Scale Model for Turbulent Mixing 43
1.6 Modelling of Turbulence–Chemistry Interaction 45
1.6.1 Direct Closure of Chemical Source Term 46
1.6.2 Eddy Breakup and Eddy Dissipation Model 47
1.6.3 Flame Surface Density Model 48
1.6.4 Transported PDF Methods 49
1.6.5 Presumed PDF Approach 50
1.6.5.1 Flamelet Model 50
1.6.5.2 Bray–Moss–Libby (BML) Model 51
1.6.5.3 G-Equation Model 52
1.6.6 Conditional Moment Closure Method 53
1.6.7 Multiple Mapping Conditioning Approach 54
1.6.8 Summary of Turbulent Combustion Models 55
1.7 Concluding Remarks 55
References 56
2 Detailed Kinetics in Combustion Simulation: Manifestation, Model Reduction, and Computational Diagnostics 60
Abstract 60
2.1 Intrinsic Complexities in Detailed Chemical Kinetics 60
2.2 Necessity of Adopting Realistic Chemistry in Combustion 64
2.2.1 Representative Non-monotonic Kinetic Behaviors in Homogeneous Reacting Systems 64
2.2.2 Manifestations of Non-monotonic Kinetic Behaviors in Reacting Flows 68
2.3 Methods to Accommodate Detailed Kinetics in Combustion Modeling 74
2.3.1 Model Reduction and Stiffness Removal 74
2.3.2 Methods to Accelerate Chemistry Integration 76
2.4 Analyze and Understand Combustion Simulation Results Through Computational Diagnostics 78
2.5 Concluding Remarks 80
Acknowledgements 80
References 81
3 Turbulent Combustion Simulations with High-Performance Computing 87
3.1 Introductory Remarks 87
3.2 Computational Cost of Combustion DNS 88
3.3 HPC and Hierarchical Parallelism 91
3.3.1 Distributed Memory Parallelism 91
3.3.2 Node-Level Parallelism 94
3.3.3 Data, Task and Hybrid Parallelism 100
3.4 Physics and Numerical Aspects 101
3.4.1 Governing Equations and Constitutive Laws 102
3.4.2 Compressible Versus Low-Mach Formulations 103
3.4.3 Spatial and Temporal Discretizations 104
3.4.4 An Exemplar Combustion DNS Code: S3D 107
3.5 Data Analyses 107
References 109
4 Direct Numerical Simulations for Combustion Science: Past, Present, and Future 112
Abstract 112
4.1 Introduction 112
4.2 A Brief History of Early Combustion DNS 113
4.2.1 From Nonreacting to Reacting Flow DNS 113
4.2.2 Premixed Combustion 115
4.2.2.1 3D DNS with Simple Chemistry 115
4.2.2.2 2D DNS with Detailed Chemistry 117
4.2.3 Nonpremixed Combustion and Ignition Studies 120
4.2.4 Partially Premixed Combustion 121
4.3 Recent Advances in DNS—Tera-, Petascale, and Beyond 122
4.3.1 Premixed Combustion 123
4.3.1.1 Scientific and Computational Considerations 123
4.3.1.2 Rectangular Periodic Channels 124
4.3.1.3 Spherically Expanding Flames 128
4.3.1.4 Flame–Wall Interaction 128
4.3.1.5 Temporally Evolving Shear Layer 129
4.3.1.6 Turbulent Jet Premixed Flames 130
4.3.1.7 Bluff-Body Stabilized Flames 130
4.3.2 Nonpremixed Combustion 131
4.3.2.1 Turbulent Jet Flames 132
4.3.2.2 Temporally Evolving Shear Layer 133
4.3.2.3 Turbulent Counterflow Flames 134
4.3.2.4 Jet in Cross-Flow 134
4.4 Future Research Opportunities in Modeling and Science 135
4.4.1 New Models and Computational Capabilities 136
4.4.1.1 Physical Models 136
4.4.1.2 Computational Capabilities 138
4.4.2 Research Questions 139
Acknowledgements 140
References 140
Turbulent Premixed Combustion 146
5 Direct Numerical Simulations of Premixed Turbulent Combustion: Relevance and Applications to Engineering Computational Analyses 147
Abstract 147
5.1 Introduction 148
5.2 Computational Requirements of DNS and Its Implications 151
5.3 Engineering Relevance of DNS 159
5.3.1 An Example of DNS-Based Modelling: Closure of Unclosed Terms of Transport Equation of Turbulent Flux of Sensible Enthalpy 161
5.3.1.1 Global Features of Flame–Wall Interaction 165
5.3.1.2 Statistical Behaviour of Turbulent Scalar Flux /overline{{/rho u_{1}^{/prime /prime } h^{/prime /prime } }} 168
5.3.2 Statistical Behaviours of the Terms in Turbulent Scalar Flux Transport Equation 172
5.3.3 Modelling of the Turbulent Transport Term T_{1} 175
5.3.4 Modelling of the Pressure Gradient Terms /left( {T_{4} /plus T_{5} } /right) 179
5.3.5 Modelling of the Molecular Dissipation Terms /left( {T_{6} /plus T_{7} } /right) 183
5.3.6 Modelling of the Reaction Rate Velocity Correlation Term T_{/bf 8} 185
5.4 Final Remarks and Conclusions 187
Acknowledgements 188
References 188
6 RANS Simulations of Premixed Turbulent Flames 193
6.1 Introduction 194
6.2 Mathematical Background 194
6.2.1 General Transport Equations 194
6.2.2 Favre-Averaged Transport Equations for First Moments 197
6.3 Challenges of and Approaches to Premixed Turbulent Combustion Modeling Within RANS Framework 199
6.3.1 Combustion Progress Variable 200
6.3.2 Effects of Combustion on Turbulence and Model Challenges 207
6.3.3 Effects of Turbulence on Combustion: Problems, Physical Mechanisms, and Models 218
6.4 Turbulent Flame Closure and Flame Speed Closure Models 230
6.4.1 Equations 230
6.4.2 Extensions 234
6.4.3 Features 236
6.4.4 Validation 237
6.5 Concluding Remarks 245
References 246
7 Modeling of Turbulent Premixed Flames Using Flamelet-Generated Manifolds 253
7.1 Introduction 253
7.2 Flamelet-Generated Manifolds 255
7.2.1 Flamelet Equations 255
7.2.2 Flamelet Solutions 257
7.2.3 Storage and Retrieval 258
7.2.4 Coupling with a Flow Solver 261
7.3 Preferential Diffusion Effects 263
7.3.1 Modeling Preferential Diffusion Effects with FGM 263
7.3.2 Application in Direct Numerical Simulations 265
7.4 Large-Eddy Simulation with FGM 268
7.4.1 Modeling Unresolved Fluctuations 268
7.4.2 Application in LES of a Gas Turbine Combustor 271
7.5 Conclusions 274
References 275
8 Conditional Moment Closure for Turbulent Premixed Flames 278
8.1 Introduction 278
8.2 Conditional Moment Closure (CMC) Method 279
8.3 Selected Experimental Measurements 285
8.4 RANS-CMC Approach 288
8.5 Results and Discussion 292
8.6 Summary and Conclusion 297
References 298
Turbulent Non-premixed Combustion 300
9 Conditional Moment Closure Methods for Turbulent Non-premixed Combustion 301
9.1 Introduction 301
9.2 Formulation 303
9.2.1 RANS-CMC Formulation 304
9.2.2 RANS Closures 306
9.2.3 LES-CMC Formulation 308
9.2.4 LES Closures 309
9.2.5 Implementation 310
9.3 Applications 312
9.3.1 Gaseous Flames 312
9.3.2 Spray Flames 314
9.3.3 Differential Diffusion 315
9.3.4 Internal Combustion Engines 316
9.4 Future Perspective and Conclusions 316
References 318
10 Direct Numerical Simulation of Autoignition in Turbulent Non-premixed Combustion 321
Abstract 321
10.1 Introduction 323
10.1.1 Numerical Modeling of Autoignition 325
10.2 Direct Numerical Simulation 326
10.2.1 DNS Studies of Autoignition 327
10.2.1.1 Influence of Turbulence Parameters on Ignition Delay 330
10.3 Homogeneous Charge Compression Ignition Engine 331
10.3.1 DNS of Combustion in HCCI Engines 332
10.3.1.1 Heat Release Rate in HCCI Engine 334
10.4 Assessment of Conditional Moment Closure Model 336
10.4.1 CMC Equations 337
10.4.2 Assessment of CMC Closure Models 338
10.4.2.1 Single-Step Chemistry 339
10.4.2.2 Four-Step Chemistry 340
10.5 Conclusions 340
Acknowledgements 341
References 341
11 Soot Predictions in Higher Order Hydrocarbon Flames: Assessment of Semi-Empirical Models and Method of Moments 344
Abstract 344
11.1 Background and Objective 345
11.2 Numerical Methods 347
11.2.1 Steady Laminar Flamelet (SLFM) Approach 348
11.2.2 Radiation Modeling 349
11.2.3 Soot Modeling 350
11.2.3.1 Semi-Empirical Models 350
11.2.3.2 Method of Moments 351
11.3 Burner Details 353
11.4 Computational Details 354
11.5 Results and Discussion 356
11.5.1 Grid-Independent Study 356
11.5.2 Structure of the Flame 356
11.5.3 Soot Predictions Without Radiation 360
11.5.4 Soot Predictions with Non-gray Radiation 362
11.6 Conclusion 367
Acknowledgements 367
References 368
12 Modelling of Soot Formation in a Kerosene Spray Flame 371
Abstract 371
12.1 Introduction 373
12.2 Modelling of Liquid Fuel Spray Combustion 375
12.2.1 Continuous Phase Modelling 375
12.2.2 Dispersed Phase Flow Model 377
12.2.3 Combustion Model 379
12.2.4 Radiation Model 382
12.3 Modelling of Soot Formation 384
12.3.1 Model Equations for Soot Formation 386
12.3.2 Soot Model Optimization and Validation 387
12.4 Physical Description and Operating Conditions of the Present Problem 390
12.5 Results and Discussion 392
12.6 Conclusion 399
Acknowledgements 400
References 400
Probability Density Function Methods 403
13 Transported Probability Density Function Method for MILD Combustion 404
Abstract 404
13.1 Background 405
13.2 Turbulence-Chemistry Interaction Models 409
13.2.1 Transported PDF Models 409
13.2.1.1 LPDF Method 410
13.2.1.2 MEPDF Method 411
13.3 Delft-Jet-in-Hot-Coflow (DJHC) Burner 412
13.3.1 Test Case Details and Numerical Setup 412
13.3.2 Discussion 414
13.4 Adelaide JHC Burner 421
13.4.1 Test Case and Computational Details 421
13.5 Conclusions 432
Acknowledgements 432
References 432
14 Large-Eddy Simulation of Nonpremixed Flames by Explicit Filtering 435
14.1 Introduction 435
14.2 LES Models for Reacting and Non-reacting Flow 437
14.2.1 Explicit Filtering Model 439
14.2.2 Filtered Mass Density Function Method 439
14.3 Numerical Methods and Simulations 442
14.3.1 Monte Carlo Method for FMDF 444
14.3.2 Validation 444
14.4 LES of Nonpremixed Combustion 447
14.5 Summary 450
References 451
15 Theory and Application of Multiple Mapping Conditioning for Turbulent Reactive Flows 452
Abstract 452
15.1 Introduction 454
15.2 Concepts and Theory 456
15.2.1 Scalar Transport Equations the MMC Concept 456
15.2.2 Reference Variables and Mapping Closure 458
15.2.3 Deterministic MMC 459
15.2.4 Stochastic MMC 461
15.2.5 Generalised MMC 463
15.3 Applications of MMC 465
15.3.1 Deterministic MMC Applications 465
15.3.2 Stochastic MMC Applications 466
15.3.3 Sparse MMC-LES Applications 471
15.3.4 MMC for Premixed Combustion 475
15.4 Conclusions 477
References 477
Recent Applications of Turbulent Combustion 480
16 Recent Progress in Turbulent Combustion Modeling of Spray Flames Using Flamelet Models 481
Abstract 481
16.1 Introduction 482
16.1.1 Non-premixed Spray Combustion 482
16.1.2 Modeling Challenges 483
16.1.2.1 Spray and Hydrocarbon Chemistry 483
16.1.2.2 Turbulence-Chemistry Interaction and Stiff Chemistry 485
16.2 The Flamelet Concept 486
16.2.1 Steady and Unsteady Flamelet Models 489
16.2.2 Presumed PDF Approach in Flamelets 491
16.2.3 Representative Interactive Flamelet (RIF) Model 491
16.2.4 Tabulated Models 493
16.2.5 Tabulated Flamelet Model (TFM) 495
16.3 Engine Combustion 496
16.3.1 LES of Sprays Under IC Engine Conditions 496
16.3.2 Low-Temperature Combustion 504
16.3.2.1 Role of Turbulence-Chemistry Interaction 507
16.3.3 Detailed Chemistry Mechanisms in CFD 509
16.3.3.1 Spray Flame Simulations with Detailed Chemistry 511
16.3.3.2 Intermediate and High-Temperature Species 511
16.4 Summary 514
References 514
17 Numerical Simulation of Turbulent Combustion in Internal Combustion Engines 517
17.1 Introduction 518
17.2 Challenges in Modeling of Turbulent Combustion in ICE 519
17.3 Numerical Simulation of Turbulent Combustion in Spark-Ignition Engines and Conventional Diesel Engines 522
17.3.1 Modeling of Turbulent Combustion in SI Engines 522
17.3.2 Modeling of Turbulent Combustion in Diesel Engines 525
17.4 Numerical Simulation of Turbulent Combustion in LTC Engines 527
17.4.1 Numerical Simulation of HCCI Engines 527
17.4.2 Numerical Simulation of PPC Engines 530
17.4.3 Numerical Simulation of RCCI Engines 533
17.5 Speedup of Numerical Simulation Based on the Finite-Rate Chemistry 536
17.5.1 Multi-zone Model 537
17.5.2 Multi-zone Chemistry Coordinate Mapping Method 539
17.6 Concluding Remarks 540
References 541
18 Characterization of Turbulent Combustion Systems Using Dynamical Systems Theory 546
18.1 Introduction 548
18.1.1 Turbulent Flows 548
18.1.2 Turbulent Reactive Flows 549
18.1.3 Different Aspects of Turbulent Combustion 550
18.2 Combustion Dynamics 550
18.2.1 Thermoacoustic Instability 551
18.2.2 Traditional Approach 552
18.2.3 Dynamical Systems Theory Approach 553
18.2.4 Pulse Combustor and Its Dynamics 554
18.3 Numerical Continuation of a Model Pulse Combustor: A Case Study 556
18.3.1 Varying Tailpipe Friction Factor (f) 561
18.3.2 Varying Wall Temperature (Tw) 563
18.3.3 Varying Convective Heat Transfer Coefficient (h) 565
18.3.4 Varying Inlet Temperature (barTi0) 566
18.3.5 Varying Inlet Fuel Mass Fraction (yf,i) 567
References 569
19 On the Theory and Modelling of Flame Acceleration and Deflagration-to-Detonation Transition 571
Abstract 571
19.1 Introduction 571
19.2 Motivation 573
19.3 Background 574
19.4 Flame Acceleration in “Combustion Tubes” 575
19.5 Summary 583
Acknowledgements 584
References 584
20 Combustion in Supersonic Flows and Scramjet Combustion Simulation 586
Abstract 586
20.1 Introduction 587
20.1.1 Physics of Combustion in Supersonic Flows with Regard to Scramjets 587
20.2 Key Equations 594
20.2.1 Navier--Stokes Equations for Multispecies Reacting Gas Flow 594
20.2.2 Examples of Kinetic Schemes for Simulation of Scramjets 598
20.3 Averaged and Filtered Conservation Equations 602
20.3.1 Reynolds Time Averaging Navier--Stokes Equations. RANS/URANS Equations 603
20.3.2 Spatially Filtered Navier--Stokes Equations. LES Approach 605
20.3.3 RANS, URANS, and LES for Compressible Reacting Flows 607
20.4 The Closure Problems 609
20.4.1 URANS/RANS Closure Models for Turbulent Fluxes 609
20.4.2 LES Closure Models for Turbulent Fluxes 616
20.4.3 Closure Problems for Reaction Rates 620
20.5 LES-Transported PaSR Model: Multiphase Approach 622
20.5.1 Basic Physical Hypothesis of EDC, PaSR, and TPaSR Models 622
20.5.2 Assumptions Made in EDC Model 624
20.5.3 TPaSR Model: Multiphase Approach for Subgrid Combustion Modeling 625
20.5.3.1 Subgrid Stress Tensor, Species Mass, and Heat Flux Vectors Closure 625
20.5.3.2 A Multiphase Approach for Subgrid Combustion Modeling 627
20.5.4 Subgrid Modeling Exchange Terms 632
20.5.5 Subgrid Time and Equilibrium Volume Fraction of the Fine Structures 634
20.5.5.1 Subgrid Time Closure 634
20.5.5.2 Equilibrium Volume Fraction of the Fine Structures 635
20.5.6 LES-TPaSR Model Governing Equations 637
20.5.6.1 The First Set of Equations 637
20.5.6.2 The Second Set of Equations 638
20.5.6.3 The Simplified LES-TPaSR Model 639
20.5.7 Reduction of LES-TPaSR Model to LES-PaSR Model 640
20.5.8 LES-TPaSR Model with Regard to Other LES Combustion Models 642
20.6 Simulation of Supersonic Jet Flame with LES—UPASR Model 644
20.6.1 The LES—Unsteady PASR (UPASR) Model 644
20.6.2 Simulation of Supersonic Hydrogen Jet Flame 645
20.7 Multiple Solutions in the PaSR Model 646
20.7.1 The Case T? lessthan Tcr 649
20.7.2 The Case T? greaterthan Tcr. Single Solution 651
20.7.3 Solution Selection Problem 651
20.8 Concluding Remarks 652
Acknowledgements 653
21 Erratum to: Large-Eddy Simulation of Nonpremixed Flames by Explicit Filtering 662
Erratum to:& #6
Author Index 663