Seventh IUTAM Symposium on Laminar-Turbulent Transition (eBook)

186838_1_En_BookFrontmatter_OnlinePDF.pdf 1
Seventh IUTAMSymposium on Laminar-Turbulent Transition 3
Contents 5
Preface 14
186838_1_En_1_Chapter_OnlinePDF.pdf 25
A Gradient-based Optimization Method for Natural Laminar Flow Design 25
1 Introduction 25
2 Governing equations 26
3 Optimization problem 27
4 Results 28
5 Conclusions 31
References 32
186838_1_En_2_Chapter_OnlinePDF.pdf 33
A Thermodynamic Lower Bound on Transition-Triggering Disturbances 33
1 Oscillators versus Amplifiers 33
1.1 Receptivity 33
1.2 Can transition be indefinitely delayed? 34
2 Fluctuation theory 34
2.1 One-dimensional: Langevin 34
2.1.1 Fluctuation-dissipation relationship in the frequency domain 35
2.1.2 Fluctuation-dissipation relationship in the time domain 36
2.2 Multi-dimensional fluctuation theory: Onsager 36
2.3 Infinite-dimensional fluctuation theory: Landau-Lifschitz 37
2.3.1 Fluctuations in macroscopic motion 38
3 Boundary-layer receptivity to thermodynamic fluctuations 38
3.1 The spatial stability problem 39
4 Conclusions 40
References 40
186838_1_En_3_Chapter_OnlinePDF.pdf 41
Hypersonic boundary layer transition and control 41
1 Experiments on nonlinear instability of hypersonic boundary layers at moderate Mach numbers 41
1.1 Experimental equipment 42
1.2 Statistical and bispectral analysis 42
1.3 Experimental results 42
2 Active control of hypersonic shock layer instability: direct numerical simulation and experiments 45
2.1 Experimental equipment and diagnostic methods 45
2.2 Numerical simulation 46
2.3 Results 46
References 48
186838_1_En_4_Chapter_OnlinePDF.pdf 49
Instabilities of Miscible Interfaces 49
1 Miscible core-annular flows 49
2 Miscible Hele-Shaw displacements 50
3 Miscible porous media displacements 53
References 55
186838_1_En_5_Chapter_OnlinePDF.pdf 57
Large-eddy simulations of relaminarization due to freestream acceleration 57
1 Introduction 57
2 Problem formulation 58
3 Results and discussion 59
4 Conclusions 63
References 64
186838_1_En_6_Chapter_OnlinePDF.pdf 65
Reduced-order models for flow control: balanced models and Koopman modes 65
1 Introduction 65
2 Model reduction techniques 66
2.1 Proper Orthogonal Decomposition and its limitations 66
2.2 Balanced models 67
3 Spectral analysis of nonlinear flows 67
3.1 Koopman operator and Koopman modes 68
3.2 Properties of Koopman modes and eigenvalues 69
3.3 Computing Koopman modes from snapshots 69
3.4 Example: jet in crossflow 70
3.5 Comparison with linear global modes and POD modes 71
References 72
186838_1_En_7_Chapter_OnlinePDF.pdf 73
The description of fluid behavior by coherent structures 73
1 Introduction and motivation 73
2 Global stability analysis of compressible flow about a swept parabolic body 74
3 Microlocal stability analysis of swept attachment-line boundary layer flow 75
4 Dynamic mode analysis of the wake behind a flexible membrane 77
5 Summary and conclusions 79
References 80
186838_1_En_8_Chapter_OnlinePDF.pdf 81
Instability of uniform turbulent plane Couette flow: spectra, probability distribution functions and K m closure model 81
1 Turbulent-laminar bands 81
2 Analysis of Fourier spectra 83
3 Stability analysis of K m Model 85
References 87
186838_1_En_9_Chapter_OnlinePDF.pdf 90
Sensitivity to base-flow variation of a streamwise corner flow 90
1 Introduction 90
2 Temporal asymptotic linear stability. 91
3 Sensitivity analysis 93
3.1 Sensitivity functions 93
3.2 Optimal deviation and physical mechanism 93
4 Conclusion 95
References 95
186838_1_En_10_Chapter_OnlinePDF.pdf 96
Transition Control Testing in the Supersonic S2MAWind Tunnel (SUPERTRAC project) 96
1 Introduction 96
2 Wing Definition 97
3 Control by Micron-Sized Roughness elements (MSR) 97
4 Control of the leading edge contamination (ACD) 99
5 Conclusion 101
6 Acknowledgements 101
References 101
186838_1_En_11_Chapter_OnlinePDF.pdf 102
Breakdown of Low-Speed Streaks under High-Intensity Background Turbulence 102
1 Introduction 102
2 Experimental setup and procedure 103
3 Results and discussion 104
4 Conclusions 107
References 107
186838_1_En_12_Chapter_OnlinePDF.pdf 108
Numerical Study on Transition of a Channel Flow with LongitudinalWall-oscillation 108
1 Introduction 108
2 Numerical Analysis 109
2.1 Model Flow 109
2.2 Results 110
3 Linear Stability Analysis 111
3.1 Quaisi steady analysis 111
3.2 Results 112
4 Conclusion 113
References 113
186838_1_En_13_Chapter_OnlinePDF.pdf 114
Direct Numerical Simulation of the Mixing Layer past Serrated Nozzle Ends 114
1 Introduction and Numerical Method 114
2 Results 115
3 Conclusions 119
References 119
186838_1_En_14_Chapter_OnlinePDF.pdf 120
Receptivity of a supersonic boundary layer to shock-wave oscillations 120
1 Introduction 120
2 Numerical Method 121
3 Results 121
4 Conclusions 125
References 125
186838_1_En_15_Chapter_OnlinePDF.pdf 126
Roughness receptivity studies in a 3-D boundary layer – Flight tests and computations 126
1 Introduction 126
2 Cp Measurements 127
3 Critical DREs 128
4 Receptivity Measurements 129
5 Receptivity Results 130
References 131
186838_1_En_16_Chapter_OnlinePDF.pdf 132
DNS investigations of steady receptivity mechanisms on a swept cylinder 132
1 Geometry, main assumptions 132
2 Unexpected unsteady fluctuation 133
3 Steady perturbation 134
3.1 Considered shapes of the perturbation 135
3.2 Steady crossflow mode 135
3.3 Influence of the roughness element shape 136
References 137
186838_1_En_17_Chapter_OnlinePDF.pdf 138
Experimental Study of the Incipient Spot Breakdown Controlled by Riblets 138
1 Introduction 138
2 Experimental Setup and Measurement Procedure 139
3 Results and Discussion 140
4 Conclusions 142
References 142
186838_1_En_18_Chapter_OnlinePDF.pdf 144
Control of Stationary Cross-flow Modes Using Patterned Roughness at Mach 3.5 144
1 Experimental Approach 145
2 Results 146
2.1 Flow Visualization 146
2.2 Mean Velocity Measurements 147
3 Conclusions 148
References 149
186838_1_En_19_Chapter_OnlinePDF.pdf 150
Secondary optimal growth and subcritical transition in the plane Poiseuille flow 150
1 Introduction and background 150
2 Results and discussion 152
References 155
186838_1_En_20_Chapter_OnlinePDF.pdf 156
Disturbance evolution in rotating-disk boundary layers: competition between absolute instability and global stability 156
1 Introduction 156
2 Modelling of numerical simulation results 157
3 Simulation results for cases with mass transfer 158
4 Summary 161
References 161
186838_1_En_21_Chapter_OnlinePDF.pdf 162
Instabilities due a vortex at a density interface: gravitational and centrifugal effects 162
1 Introduction 162
2 Centrifugal effects 163
3 Gravitational effects 165
4 Conclusions and outlook 166
References 167
186838_1_En_22_Chapter_OnlinePDF.pdf 168
Wave Packets of Controlled Velocity Perturbations at Laminar Flow Separation 168
1 Introduction 168
2 Experimental set-up 169
3 Results and discussion 170
References 173
186838_1_En_23_Chapter_OnlinePDF.pdf 174
Linear Stability Analysis for Manipulated Boundary-Layer Flows using Plasma Actuators 174
1 Introduction 174
2 Linear Stability Analysis 175
3 Results 176
4 Discussion 179
References 179
186838_1_En_24_Chapter_OnlinePDF.pdf 180
Stripy patterns in low-Re turbulent plane Couette flow 180
1 Introduction 180
2 Results 181
2.1 Numerical method 181
2.2 Formation of stripes 182
References 185
186838_1_En_25_Chapter_OnlinePDF.pdf 186
Characterization of the three-dimensiona linstability in a lid-driven cavity by an adjoint based analysis 186
1 Introduction 186
2 Governing equations and solution method 187
3 Results 188
References 191
186838_1_En_26_Chapter_OnlinePDF.pdf 192
Bi-global crossplane stability analysis of high-speed boundary-layer flows with discrete roughness 192
1 Introduction 192
2 Bi-global secondary linear stability theory & numerics
3 Primary state 193
4 Results 194
5 Conclusions 197
References 197
186838_1_En_27_Chapter_OnlinePDF.pdf 198
Time-resolved PIV investigations on the laminar-turbulent transition over laminar separation bubbles 198
1 Introduction 198
2 Experimental setup and data evaluation 199
3 Results 199
4 Conclusion 202
References 202
186838_1_En_28_Chapter_OnlinePDF.pdf 204
Control of transient growth induced boundary layer transition using plasma actuators 204
1 Introduction 204
2 Experimental Details 205
3 Results 206
4 Conclusions and Outlook 208
References 209
186838_1_En_29_Chapter_OnlinePDF.pdf 210
Laminar Flow Control by Suction at Mach 2 210
1 Introduction 210
2 Experimental Set-Up 211
3 Experimental Results 211
4 Numerical Analyses 213
5 Conclusions 215
References 215
186838_1_En_30_Chapter_OnlinePDF.pdf 216
Decay of turbulent bursting in enclosed flows 216
1 Introduction 216
2 Methods 217
3 Results 217
4 Conclusion and outlook 220
References 221
186838_1_En_31_Chapter_OnlinePDF.pdf 222
Local and Global Stability of Airfoil Flows at Low Reynolds Number 222
1 Introduction 222
2 Behaviour with incidence 224
3 Influence of compressibility 225
4 Influence of Reynolds Number and Airfoil Geometry 225
5 Conclusion 226
References 227
186838_1_En_32_Chapter_OnlinePDF.pdf 228
Numerical simulation of riblet controlled oblique transition 228
1 Introduction 228
2 Numerical Method 229
3 Flow configuration and computational mesh 230
4 Results 230
References 231
186838_1_En_33_Chapter_OnlinePDF.pdf 234
Transition Movement in theWake of Protruding and Recessed Three-Dimensional Surface Irregularities 234
1 Introduction 234
2 Transition Measurements 235
3 Stability Calculations 236
4 Conclusions 237
References 238
186838_1_En_34_Chapter_OnlinePDF.pdf 240
Plasma Assisted Aerodynamics for Transition Delay 240
1 Introduction 240
2 Theoretical Background 241
2.1 Plasma model 241
3 Results 242
4 Conclusions and Future work 244
References 245
186838_1_En_35_Chapter_OnlinePDF.pdf 246
Experimental study on stability of the laminar and turbulent plane jets 246
1 Laminar plane jet with the abrupt mean velocity profile at the nozzle exit 246
2 A laminar and turbulent plane jet with a parabolic mean velocity profile at the nozzle exit 248
3 Plane jet approaching to the microjet 250
4 Conclusions 251
References 251
186838_1_En_36_Chapter_OnlinePDF.pdf 252
Evolution Of Traveling Crossflow Modes Over A Swept Flat Plate 252
1 Introduction 252
2 Experimental Setup 252
2.1 Turbulence generation 254
3 Results 254
3.1 Velocity and Disturbance Profiles 254
3.2 Spanwise Correlations 255
3.3 Disturbance Growth 256
4 Conclusions and Outlook 257
References 257
186838_1_En_37_Chapter_OnlinePDF.pdf 258
Computational Analysis for Roughness-Based Transition Control 258
1 Introduction 258
2 Methods 259
3 Results 259
4 Conclusions 263
References 263
186838_1_En_38_Chapter_OnlinePDF.pdf 264
Statistics of turbulent-to-laminar transition in plane Couette flow 264
1 Introduction 264
2 Model and Results 265
References 267
186838_1_En_39_Chapter_OnlinePDF.pdf 268
Spectra of Swirling Flow 268
1 Introduction 268
2 Linear asymptotical stability analysis 269
3 Optimal transient growth analysis 270
4 Map of spectra 271
5 Conclusion 273
References 273
186838_1_En_40_Chapter_OnlinePDF.pdf 274
Localized edge states for the transition to turbulence in shear flows 274
1 Introduction 274
2 Numerical methods and results 276
3 Conclusions 278
References 279
186838_1_En_41_Chapter_OnlinePDF.pdf 280
Active steady control of vortex shedding: an adjoint-based sensitivity approach 280
1 Introduction 280
2 Global stability of the cylinder flow 281
3 Adjoint-based sensitivity approach 282
4 Results 283
References 285
186838_1_En_42_Chapter_OnlinePDF.pdf 286
Feedback control of transient energy growth in subcritical plane Poiseuille flow 286
1 Introduction 287
2 Discretization 287
3 System properties 288
4 Control design 288
5 Results 289
6 Conclusions 291
References 291
186838_1_En_43_Chapter_OnlinePDF.pdf 292
Linear and non-linear disturbance evolution in a compressible boundary-layer with localized roughness 292
1 Introduction 292
2 Mathematical model and numerical method 293
3 Uncertainty quantification 294
4 Mean flow 294
5 Deterministic disturbance evolution 295
6 Stochastic disturbance evolution 296
7 Conclusion 297
References 297
186838_1_En_44_Chapter_OnlinePDF.pdf 298
Experimental Study of Boundary Layer Transition Subjected toWeak Free Stream Turbulence 298
1 Introducution 298
2 Experimental Set-up 299
3 Hot-wire Measurement Result and Flow Visualization 301
4 Conclution 303
References 303
186838_1_En_45_Chapter_OnlinePDF.pdf 304
Open-loop control of compressible afterbody flows using adjoint methods 304
1 Introduction 304
2 Theoretical framework 305
3 Results 307
4 Perspectives 308
References 309
186838_1_En_46_Chapter_OnlinePDF.pdf 310
Direct Numerical Simulation of a Swept-Wing Boundary Layer with an Array of Discrete Roughness Elements 310
1 Introduction 310
2 Flow Configuration and Numerical Method 311
3 Initial results and future work 313
References 315
186838_1_En_47_Chapter_OnlinePDF.pdf 316
Wave packet pseudomodes upstream of a swept cylinder 316
1 Introduction 316
2 Wave packet pseudomodes for the uniform stability problem 319
3 Conclusions 321
References 321
186838_1_En_48_Chapter_OnlinePDF.pdf 322
Bypass Transition prediction using a model based on transient growth theory 322
1 Introduction 322
2 Governing equations 323
3 Wall normal velocity fluctuation modelling 324
4 Results 324
5 Conclusion 326
References 327
186838_1_En_49_Chapter_OnlinePDF.pdf 328
Flow in a Slowly Divergent Pipe Section 328
1 Introduction 328
2 Experimental Setup 329
3 Results and Discussions 331
4 Conclusions 332
References 333
186838_1_En_50_Chapter_OnlinePDF.pdf 334
In-flight experiments on active TS-wave control on a 2D-laminar wing glove 334
1 Introduction 334
2 Experimental setup 335
3 Control algorithm 336
4 Results 337
5 Conclusions 339
References 339
186838_1_En_51_Chapter_OnlinePDF.pdf 340
Global nonlinear dynamics of thin aerofoil wakes 340
1 Introduction 340
2 Global nonlinear dynamics obtained by direct numerical simulations 341
3 Basic flow and local absolute frequencies 342
4 Discussion 344
References 345
186838_1_En_52_Chapter_OnlinePDF.pdf 346
Riccati-less optimal control of bluff-body wakes 346
1 Background 346
2 Riccati-less optimal control 348
3 Application 350
References 351
186838_1_En_53_Chapter_OnlinePDF.pdf 352
Asymptotic theory of the pre-transitional laminar streaks and comparison with experiments 352
1 Introduction 352
2 Mathematical formulation 353
3 Results 355
4 Conclusions and Outlook 356
References 357
186838_1_En_54_Chapter_OnlinePDF.pdf 358
Roughness-induced transition of compressible laminar boundary layers 358
1 Introduction 358
2 Method 359
3 Flow structure 360
4 Critical threshold 361
5 Conclusion 362
References 363
186838_1_En_55_Chapter_OnlinePDF.pdf 364
On receptivity and modal linear instability of laminar separation bubbles at all speeds 364
1 Introduction and Motivation 364
2 Theory and Numerical Methods 365
3 Results 366
3.1 Incompressible flow 366
3.1.1 Receptivity and sensitivity of LSB flow 366
3.1.2 U-separation and Stall Cells 367
3.2 Compressible flow 368
3.2.1 Subsonic flow: the effect of compressibility 368
3.2.2 Supersonic regime: SBLI and supersonic finite-angle wedge flows 368
References 369
186838_1_En_56_Chapter_OnlinePDF.pdf 370
Hypersonic instability waves measured on a circular cone at M=12 using fast-response surface heat-flux and pressure gauges 370
1 Introduction 370
2 Experimental Setup 370
3 Experimental Results 372
References 375
186838_1_En_57_Chapter_OnlinePDF.pdf 376
Interaction of noise disturbances and streamwise streaks 376
1 Introduction and Numerical Method 376
2 Numerical Method 377
3 Results 378
4 Conclusions 381
References 381
186838_1_En_58_Chapter_OnlinePDF.pdf 382
Experimental study on the use of the wake instability as a passive control in coaxial jet flows 382
1 Introduction 382
2 Experimental arrangement 383
3 Results 384
4 Conclusions 387
References 387
186838_1_En_59_Chapter_OnlinePDF.pdf 388
Numerical and Experimental Investigations of Relaminarizing Plane Channel Flow 388
1 Introduction 388
2 Numerical Method and Experimental Setup 389
2.1 Numerical Method 389
2.2 Experimental Facility and Measurement Technique 390
3 Results 390
4 Conclusion 393
References 393
186838_1_En_60_Chapter_OnlinePDF.pdf 394
Linear control of 3D disturbances on a flat-plate 394
1 Input-output configuration 394
2 Model reduction 396
3 Controller design 398
References 399
186838_1_En_61_Chapter_OnlinePDF.pdf 400
Experimental study of stability of supersonic boundary layer on swept wing 400
1 Introduction 400
2 Experimental equipment 401
3 Stability 402
4 Conclusions 404
References 405
186838_1_En_62_Chapter_OnlinePDF.pdf 406
Comparison of Direct Numerical Simulation with the Theory of Receptivity in a Supersonic Boundary Layer 406
1 Introduction 406
2 Problem formulation 407
3 Analysis and results 408
4 Conclusions 410
References 411
186838_1_En_63_Chapter_OnlinePDF.pdf 412
Instability of high Mach number flows in the presence of high-temperature gas effects 412
1 Introduction 412
2 Numerical Method 413
2.1 Results 414
2.1.1 Instability development in the M=20 flat plate boundary layer 414
2.2 Flow around the cuboid in the HyBoLT configuration 415
2.3 Conclusions 416
References 417
186838_1_En_64_Chapter_OnlinePDF.pdf 418
Spatially localised growth within global instabilities of flexible channel flows 418
1 Introduction 418
2 The model 419
3 Methods 421
4 Results 422
5 Discussion 422
References 423
186838_1_En_65_Chapter_OnlinePDF.pdf 424
Global stability of a plane liquid jet surrounded by gas 424
1 Introduction 424
2 Flow modelling, numerical implementation and verification 426
3 Results and discussion 428
4 Conclusions and outlook 429
References 429
186838_1_En_66_Chapter_OnlinePDF.pdf 430
Instabilities of flow in a corrugated pipe 430
1 Introduction 430
2 A model of corrugated pipe and stability analysis 431
3 Conclusions 435
References 435
186838_1_En_67_Chapter_OnlinePDF.pdf 436
The Late Nonlinear Stage of Oblique Breakdown to Turbulence in a Supersonic Boundary Layer 436
1 Introduction 436
2 Computational Setup 437
3 Initiating the Oblique Breakdown Mechanism 438
4 The Late Nonlinear Stage of Breakdown 439
5 Reaching Fully Developed Turbulence 440
6 Conclusions 441
References 441
186838_1_En_68_Chapter_OnlinePDF.pdf 442
Turbulence stripe in transitional channel flow with/without system rotation 442
1 Introduction 442
2 Numerical and experimental descriptions 443
3 Results 444
3.1 DNS on PPF and PCF 444
3.2 Flow visualization on PPF and RPCF 445
4 Conclusions 447
References 447
186838_1_En_69_Chapter_OnlinePDF.pdf 448
Direct Numerical Simulation and Theoretical Analysis of Perturbations in Hypersonic Boundary Layers 448
1 Introduction 448
2 Outline of the method 449
3 Numerical Approach 450
4 Results 450
4.1 Flat plate 450
4.2 Wedge 453
References 453
186838_1_En_70_Chapter_OnlinePDF.pdf 454
Flow Transition in Free Liquid Film Induced by Thermocapillary Effect 454
1 Introduction 454
2 Target Geometry 455
3 Numerical Simulation 456
4 Experiment 456
5 Results & Discussion
6 Concluding Remarks 459
References 459
186838_1_En_71_Chapter_OnlinePDF.pdf 460
Boundary layer transition by interaction of streaks and Tollmien–Schlichting waves 460
1 Introduction 461
2 Interaction of streaks and Tollmien–Schlichting waves 462
Continuous-discrete mode interactions 462
The influence of free-stream turbulence 464
References 465
186838_1_En_72_Chapter_OnlinePDF.pdf 466
Numerical Investigation of Subharmonic Resonance Triads in a Mach 3 Boundary Layer 466
1 Introduction 466
2 Computational Setup 467
3 Subharmonic Resonance Triad 468
4 DNS of Oblique-Subharmonic Resonance Triad 469
5 DNS of the Interaction of Oblique-Subharmonic Resonance with Oblique Breakdown 470
6 Conclusions 471
References 471
186838_1_En_73_Chapter_OnlinePDF.pdf 473
Transient Growth on the Homogenous Mixing Layer 473
1 Introduction 473
2 Hyperbolic Tangent Velocity Profile 474
3 Developing KH billow 476
References 476
186838_1_En_74_Chapter_OnlinePDF.pdf 477
Closed-loop control of cavity flow using a reduced-order model based on balanced truncation 477
1 Introduction 477
2 Configuration, modeling and model reduction 478
3 LQG control 478
4 Comparison with reduced model based on POD and global modes 480
5 Conclusions and Outlook 480
References 480
186838_1_En_75_Chapter_OnlinePDF.pdf 481
On the asymptotic solution of the flow around a circular cylinder 481
1 Introduction 481
2 Numerical Simulations 482
3 Experiments and DPIV Mesurements 482
4 Results: harmonic fields and amplitudes 483
5 Acknowledgements 484
References 484
186838_1_En_76_Chapter_OnlinePDF.pdf 485
Investigations of Suction in a Transitional Flat-Plate Boundary Layer 485
1 Introduction 485
2 Experimental setup 486
3 Results 487
4 Conclusion 488
References 488
186838_1_En_77_Chapter_OnlinePDF.pdf 489
Global three-dimensional optimal perturbations in a Blasius boundary layer 489
1 Introduction 489
2 Problem formulation 490
3 Results and discussion 490
References 492
186838_1_En_78_Chapter_OnlinePDF.pdf 493
Quantifying sub-optimal transient growth using biorthogonal decomposition 493
1 Motivation 493
2 Method 494
3 Results 495
References 496
186838_1_En_79_Chapter_OnlinePDF.pdf 497
Model reduction using Balanced Proper Orthogonal Decomposition with frequential snapshots 497
1 Introduction 497
2 Flow configuration 498
3 Model reduction 498
4 Input-output response 499
5 Conclusions and Outlook 500
References 500
186838_1_En_80_Chapter_OnlinePDF.pdf 501
Control of a trapped vortex in a thick airfoil by steady/unsteady mass flow suction 501
1 Introduction 501
2 Experimental Setup and Measurements Instrumentation 501
3 Experimental Test Campaign 502
3.1 No-Suction and Steady Suction 502
3.2 Unsteady Suction 503
4 Results 503
5 Conclusions 504
References 504
186838_1_En_81_Chapter_OnlinePDF.pdf 505
Receptivity of compressible boundary layer to kinetic fluctuations 505
1 Introduction 505
2 Analysis and results 506
3 Conclusions 508
References 508
186838_1_En_82_Chapter_OnlinePDF.pdf 509
Effect of transport modeling on hypersonic cooled wall boundary layer stability 509
1 Introduction 509
2 Methodology 510
3 Results 511
4 Conclusion 512
References 512
186838_1_En_83_Chapter_OnlinePDF.pdf 513
Modeling Supersonic and Hypersonic Flow Transition over Three-Dimensional Bodies 513
1 Introduction 513
2 Model formulation 514
3 Results and discussion 514
4 Conclusion 516
References 516
186838_1_En_84_Chapter_OnlinePDF.pdf 517
Amplitude threshold in the wake transition of an oscillating circular cylinder 517
1 Introduction 517
2 Results 518
3 Conclusions 519
4 Acknowledgements 520
References 520
186838_1_En_85_Chapter_OnlinePDF.pdf 521
Certain Aspect of Instability of Flow in a Channel with Expansion/Contraction 521
1 Introduction 521
2 Numerical procedure 522
3 Results and Discussion 523
References 523
186838_1_En_86_Chapter_OnlinePDF.pdf 525
Some properties of boundary layer under the joint effect of external flow turbulence and surface roughness 525
1 Introduction 525
2 Experiment and results 526
3 Conclusions 527
References 528
186838_1_En_87_Chapter_OnlinePDF.pdf 529
Wave forerunners of localized structures at the boundary layer 529
1 Introduction 529
2 Experimental set-up 529
3 Results 530
4 Conclusions 532
References 532
186838_1_En_88_Chapter_OnlinePDF.pdf 533
Experiments on the wave train excitation and wave interaction in spanwise modulated supersonic boundary layer 533
1 Introduction 533
2 Experiments set-up 534
3 Results 534
3.1 Initial Amplitudes of Wave Trains 535
3.2 Nonlinear Wave Train Development 535
4 Conclusions 536
References 536
186838_1_En_89_Chapter_OnlinePDF.pdf 537
Laminar-Turbulent Transition and Boundary Layer Separation on wavy surface wing 537
1 Introduction 537
2 Experimental Apparatus 538
3 Results 538
4 Conclusion 539
References 539
186838_1_En_90_Chapter_OnlinePDF.pdf 540
Investigation of Thermal Nonequilibrium on Hypersonic Boundary-Layer Transition by DNS 540
1 Gas Models 540
2 Results 541
3 Conclusions 543
References 543
186838_1_En_91_Chapter_OnlinePDF.pdf 544
Global sustained perturbations in a backward-facing step flow 544
1 Introduction 544
2 Global sustained perturbations 545
3 Results 547
References 547
186838_1_En_92_Chapter_OnlinePDF.pdf 548
Large Reynolds number streak description using RNS 548
1 RNS streak formulation 548
2 Results and Conclusions 550
3 Acknowledgments 551
References 551
186838_1_En_93_Chapter_OnlinePDF.pdf 552
Optimal disturbances with iterative methods 552
1 Optimal disturbances with iterative methods 552
2 Results 553
3 Conclusions 555
References 555
186838_1_En_94_Chapter_OnlinePDF.pdf 556
Connection between full-lifetime and breakdown of puffs in transitional pipe flows 556
1 Introduction 556
2 Experimental test rig 557
3 Measurement of a full-lifetime of puffs and a rate of splitting puffs’ occurrence 557
4 Conclusions and final remarks 558
References 559
186838_1_En_95_Chapter_OnlinePDF.pdf 560
Effect of oblique waves on jet turbulence 560
1 Introduction 560
2 Motivation for experiments 561
3 Results and Discussion 562
References 563
186838_1_En_96_Chapter_OnlinePDF.pdf 564
The effect of a single three-dimensional roughness element on the boundary layer transition 564
1 Introduction 564
2 Experimental Set-up and Results 565
3 Final remarks 565
References 567
186838_1_En_97_Chapter_OnlinePDF.pdf 568
Experimental study of resonant interactions of modulated waves in a non self-similar boundary layer 568
1 Introduction 568
2 Results 569
3 Conclusions 570
References 571
186838_1_En_98_Chapter_OnlinePDF.pdf 572
High Reynolds Number Transition Experiments in ETW (TELFONA project) 572
1 Introduction 572
2 Model Design and measurement systems 573
3 Analysis and stabilty calculations 574
4 Conclusion 575
186838_1_En_99_Chapter_OnlinePDF.pdf 576
Entropy generation rate in turbulent spots in a boundary layer subject to freestream turbulence 576
1 Introduction 576
2 Results and Discussion 577
2.1 Spot Evolution 577
2.2 Entropy generation 578
3 Conclusions 578
References 579
186838_1_En_100_Chapter_OnlinePDF.pdf 580
The Effect of a Particle travelling through a Laminar Boundary Layer on Transition 580
1 Background 580
2 ExperimentalWork 581
3 NumericalWork 582
4 Concluding Remarks 583
References 583
186838_1_En_101_Chapter_OnlinePDF.pdf 584
Flow past a plate with elliptic leading edge: layer response to free-stream vorticity 584
1 Introduction 584
2 Flow Model and Numerical Approach 585
3 Results 585
References 587
186838_1_En_102_Chapter_OnlinePDF.pdf 588
Fluctuation Measurements in the Turbulent Boundary Layer of a Supersonic Flow 588
1 Introduction 588
2 Experimental Facility 589
3 Measurement Devices and Data Evaluation 589
4 Results and Discussion 590
5 Conclusions and Outlook 591
References 591
186838_1_En_103_Chapter_OnlinePDF.pdf 592
Experimental characterization of the transition region in a rotating-disk boundary layer 592
1 Introduction 592
2 Experimental setup 593
3 Mean-velocity profiles 593
4 Spectral analysis 593
5 Conclusions and outlook 595
References 595
186838_1_En_104_Chapter_OnlinePDF.pdf 596
Nonlinear Interaction BetweenWavepackets in Plane Poiseuille Flow 596
1 Introduction 596
2 Equations, Numerical Methods and Initial Condition 597
3 Results 597
4 Final Remarks 598
References 599
186838_1_En_105_Chapter_OnlinePDF.pdf 600
Effects of Passive PorousWalls on Hypersonic Boundary Layers 600
1 Introduction 600
2 Linear Stability Problem 601
3 Results 602
4 FutureWork 602
References 603
186838_1_En_106_Chapter_OnlinePDF.pdf 604
Global Instabilities inWall Jets 604
1 Introduction 604
2 Formulation and Numerical Method 605
3 Results 605
4 Conclusions 607
References 607
186838_1_En_107_Chapter_OnlinePDF.pdf 608
Spatial Optimal Disturbances in Three-Dimensional Boundary Layers 608
1 Introduction 608
2 Methodology 609
3 Results 610
References 611
186838_1_En_108_Chapter_OnlinePDF.pdf 612
Influence of turbulence scale and shape of leading edge on laminar-turbulent transition induced by free-stream turbulence 612
1 Introduction 612
2 Linear receptivity theory to FST 613
3 Experimental results 614
References 615
186838_1_En_109_Chapter_OnlinePDF.pdf 616
Bifurcation characteristics of the channel flow on a rotating system undergoing transition under the influence of the Coriolis force 616
1 Introduction and scope of the present work 616
2 The governing equations 617
3 Outline of the method 617
4 Conclusions and Outlook 619
References 619
186838_1_En_110_Chapter_OnlinePDF.pdf 620
Linear Stability Investigations of Flow Over Yawed Anisotropic CompliantWalls 620
1 Introduction 620
2 Theoretical Model of the Yawed AnisotropicWall 620
3 Numerical Method and Code Validation 621
4 Results 622
5 Conclusions 622
References 623
186838_1_En_BookBackmatter_OnlinePDF.pdf 624
Author Index 624
Part I Invited Presentations 24
Part II Oral Presentations 89
Part III Poster Presentations 472