Peinke / Oberlack Progress in Turbulence III

Proceedings of the iTi Conference in Turbulence 2008
1. Auflage 2009
ISBN: 978-3-642-02225-8
Verlag: Springer
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 268 Seiten

This third issue on “progress in turbulence” is based on the third ITI conference (ITI interdisciplinary turbulence initiative), which took place in Bertinoro, North Italy. Researchers from the engineering and physical sciences gathered to present latest results on the rather notorious difficult and essentially unsolved problem of turbulence. This challenge is driving us in doing basic as well as applied research. Clear progress can be seen from these contributions in different aspects. New - phisticated methods achieve more and more insights into the underlying compl- ity of turbulence. The increasing power of computational methods allows studying flows in more details. Increasing demands of high precision large turbulence - periments become aware. In further applications turbulence seem to play a central issue. As such a new field this time the impact of turbulence on the wind energy conversion process has been chosen. Beside all progress our ability to numerically calculate high Reynolds number turbulent flows from Navier-Stokes equations at high precision, say the drag co- ficient of an airfoil below one percent, is rather limited, not to speak of our lack of knowledge to compute this analytically from first principles. This is rather - markable since the fundamental equations of fluid flow, the Navier-Stokes eq- tions, have been known for more than 150 years.

Autoren/Hrsg.

Peinke, Joachim

Oberlack, Martin

Inhaltsverzeichnis

1;Preface;6
2;Contents;8
3;Turbulence;8
3.1;Fully Developed Turbulence with Diminishing Mean Vortex Stretching and Reduced Intermittency;14
3.1.1;References;21
3.2;Spectral and Physical Forcing of Turbulence;22
3.2.1;Introduction;22
3.2.2;Stochastic and Linear Forcing;23
3.2.3;Results and Discussion;23
3.2.4;Conclusion;25
3.2.5;References;25
3.3;Fractal-Generated Turbulent Scaling Laws from a New Scaling Group of the Multi-Point Correlation Equation;26
3.3.1;Multi-Point Equation in the Limit of Homogeneous Turbulence;26
3.3.2;Symmetries of the Multi-Point Equation;28
3.3.3;Invariant Solutions and Turbulent Decay Scaling Laws;28
3.3.4;Conclusions;32
3.3.5;References;32
3.4;Investigation of the Conditional Scalar Dissipation Rate Across a Shear Layer Using Gradient Trajectories;33
3.4.1;Introduction;33
3.4.2;Results;34
3.4.3;Conclusions;36
3.4.4;References;36
3.5;‘Rational’ Turbulence Models?;37
3.5.1;Models for Homogeneous Isotropic Turbulence;37
3.5.2;Models for Inhomogeneous Turbulence;39
3.5.3;References;40
3.6;An Approximation of the Invariant Measure for the Stochastic Navier-Stokes;41
3.6.1;Introduction;41
3.6.2;Fluid Flow and Ito Diffusion;41
3.6.3;The Approximation;42
3.6.4;References;44
3.7;Spatial Multi-Point Correlations in Inhomogeneous Turbulence;45
3.7.1;Introduction – Closure Problem and Stochastic Processes;45
3.7.2;Experimental Results – Markov Properties;47
3.7.3;References;48
3.8;Statistical Properties of Velocity Increments in Two-Dimensional Turbulence;49
3.8.1;Introduction;49
3.8.2;Numerical Treatment and Statistical Analysis;50
3.8.3;Conclusion;51
3.8.4;References;52
3.9;Enstrophy Transfers Study in Two-Dimensional Turbulence;53
3.9.1;The Interaction Function;53
3.9.2;Experimental Setup and Numerical Results;54
3.9.3;Conclusion;55
3.9.4;References;56
3.10;Two Point Velocity Difference Scaling along Scalar Gradient Trajectories in Turbulence;57
3.10.1;Introduction;57
3.10.2;Theory and Results;58
3.10.3;Conclusions;60
3.10.4;References;60
3.11;Stochastic Analysis of Turbulence n-Scale Correlations in Regular and Fractal-Generated Turbulence;61
3.11.1;Introduction;61
3.11.2;Results for Fractal-Generated Turbulence;62
3.11.3;References;64
4;Experimental Methods;9
4.1;Holographic PIV with Low Coherent Light – Recent Progress in 3D Flow Measurements;65
4.1.1;Principles of Holographic PIV;65
4.1.2;Noise Problem and Light-in-Flight Configuration;66
4.1.3;Measurements;67
4.1.4;Conclusions;68
4.1.5;References;68
4.2;An Experimental Demonstration of Accelerated Tomo-PIV;69
4.2.1;Introduction;69
4.2.2;An Experimental Assessment of Accelerated Tomo-PIV;70
4.2.3;Conclusions;72
4.2.4;References;72
4.3;Using the 2D Laser-Cantilever-Anemometer for Two-Dimensional Measurements in Turbulent Flows;73
4.3.1;LCA - Basic Principle;73
4.3.2;Development of the 2D LCA;74
4.3.3;Measurements with 2DLCA and x-Wire;75
4.3.4;Conclusions;76
4.3.5;Reference;76
4.4;3D Structures from Stereoscopic PIV Measurements in a Turbulent Boundary Layer;77
4.4.1;Introduction;77
4.4.2;Experiment;78
4.4.3;Results;78
4.4.4;Summary;80
4.4.5;References;80
4.5;The Sphere Anemometer – A Fast Alternative to Cup Anemometry;81
4.5.1;Sphere Anemometer Principle and Setup;82
4.5.2;Measurements;83
4.5.3;Conclusions;84
4.5.4;References;84
4.6;CICLoPE – A Large Pipe Facility for Detailed Turbulence Measurements at High Reynolds Number;85
4.6.1;Fully Resolved High Reynolds Number Experiment;86
4.6.2;The Long Pipe Facility at CICLoPE;87
4.6.3;The CICLoPE Laboratory;88
4.6.4;References;89
5;Wind Energy;9
5.1;Aerodynamics of an Airfoil at Ultra-Low Reynolds Number;90
5.1.1;Introduction;90
5.1.2;Experimenral Details;91
5.1.3;Results and Discussion;91
5.1.4;Conclusion;92
5.1.5;References;93
5.2;Turbulence Energetics in Stably Stratified Atmospheric Flows;94
5.2.1;Energy and Flux Budget Turbulence Closure Model;95
5.2.2;Effect of Large-Scale Internal GravityWaves;96
5.2.3;Conclusions;97
5.2.4;References;97
5.3;Measurements of the Flow Upstream a Rotating Wind Turbine Model;98
5.3.1;Introduction;98
5.3.2;Experimental Conditions;99
5.3.3;Results;100
5.3.4;References;101
5.4;Is the Meandering of aWind TurbineWake Due to Atmospheric Length Scales?;102
5.4.1;Introduction;102
5.4.2;Experimental Set Up;103
5.4.3;Analysis;103
5.4.3.1;Temporal Study;104
5.4.3.2;Spatial study;104
5.4.4;Conclusion;105
5.4.5;References;105
5.5;Impact of Atmospheric Turbulence on the Power Output ofWind Turbines;106
5.5.1;Introduction;106
5.5.2;Characterization of Turbulent Structures;107
5.5.3;Stochastic RelaxationModel;107
5.5.4;Discussion and Concluding Remarks;109
5.5.5;References;109
5.6;About First Order Geometric Auto Regressive Processes for Boundary Layer Wind Speed Simulation;110
5.6.1;Motivation;110
5.6.2;Fluctuation Statistics;111
5.6.3;Increment Statistics;112
5.6.4;Summary;113
5.6.5;References;113
5.7;Unsteady Numerical Simulation of the Turbulent Flow around a Wind Turbine;114
5.7.1;Introduction;114
5.7.2;Configuration and Investigated Flow Case;115
5.7.3;Unsteady Numerical Simulation of the Blade Flow;115
5.7.4;Conclusion;117
5.7.5;References;117
5.8;A New Non-gaussian TurbulentWind Field Generator to Estimate Design-Loads of Wind-Turbines;118
5.8.1;Introduction;119
5.8.2;Model Description;119
5.8.2.1;Wind-Field Models;119
5.8.2.2;Wind Turbine Model;120
5.8.3;Result: Blade-Root Bending Moment;120
5.8.4;Summary and Conclusions;121
5.8.5;References;121
5.9;Synthetic Turbulence Models for Wind Turbine Applications;122
5.9.1;Introduction;122
5.9.2;Overview over Existing Models;123
5.9.2.1;Spectral Models (Category I);123
5.9.2.2;Improvements of Spectral Models (Categories II-IV);124
5.9.2.3;Probabilistic CTRW-Model (Category V);124
5.9.2.4;Modelling of Energy Cascade (Categories VI and VII);124
5.9.2.5;Multi-scale Reconstruction of Time Series (Category VIII);124
5.9.3;Summary;125
5.9.4;References;125
5.10;Numerical Simulation of the Flow around a Tall Finite Cylinder Using LES and PANS;126
5.10.1;Description of the Set-Up and Numerical Methods;126
5.10.2;Results;127
5.10.3;References;129
5.11;Large Eddy Simulation of Turbulent Flows around a Rotor Blade Segment Using a Spectral Element Method;130
5.11.1;Introduction;130
5.11.2;Results of LES for $Re$ = 5 ·10\^{3} and $Re$ = 5 ·10\^{4};131
5.11.3;References;133
6;Modelling and Simulation and Mathematics;10
6.1;Vorticity and Helicity in Swirling Pipe Flow;134
6.1.1;Introduction;134
6.1.2;Results;134
6.1.3;Conclusions;137
6.1.4;References;137
6.2;Explicit Algebraic Subgrid Models for Large Eddy Simulation;138
6.2.1;Model Description;138
6.2.2;Validation;139
6.2.3;References;140
6.3;Direct Numerical Simulation of a Turbulent Flow with Pressure Gradients;141
6.3.1;Introduction;141
6.3.2;Computational Details;142
6.3.3;Results and Discussion;142
6.3.4;References;144
6.4;An Invariant Nonlinear Eddy Viscosity Model Based on a Consistent 4D Modelling Approach;145
6.4.1;Introduction;145
6.4.2;Construction of a Newtonian Space-Time Manifold;146
6.4.3;Proposal for an Invariant Nonlinear Eddy Viscosity Model;147
6.4.4;References;148
6.5;A Hybrid URANS/LES Approach Used for Simulations of Turbulent Flows;149
6.5.1;Introduction;149
6.5.2;Problem Formulation;150
6.5.3;Results;151
6.5.4;Conclusion;152
6.5.5;References;152
6.6;Anisotropic Synthetic Turbulence with Sweeping Generated by Random Particle-Mesh Method;153
6.6.1;Introduction;153
6.6.2;Convective Moving-Average Method;154
6.6.3;Numerical Results;155
6.6.4;Conclusion;156
6.6.5;References;156
6.7;LES and Hybrid LES/RANS Study of Flow and Heat Transfer around aWall-Bounded Short Cylinder;157
6.7.1;Introduction;157
6.7.2;Models and Numerics;157
6.7.3;Discussion;158
6.7.4;Conclusions;160
6.7.5;References;160
6.8;Stochastically Forced Laminar Plane Couette Flow: Non-normality and Hydrodynamic Fluctuations;161
6.8.1;Introduction;161
6.8.2;DNS of the Stochastically Forced Plane Couette Flow;162
6.8.3;Results;163
6.8.4;References;164
6.9;Reynolds Stress Model Based on the RDT Equations and Turbulence Dynamics in the Aerodynamic Nozzle;165
6.9.1;The Paradigm of the Turbulence Model;165
6.9.2;Turbulence in Nozzles;166
6.9.3;References;168
7;Particle Laden Flows;11
7.1;Heat Transfer Modulation by Microparticles in Turbulent Channel Flow;169
7.1.1;Introduction;169
7.1.2;DNS/LPT Methodology;170
7.1.3;Results and Discussion;171
7.1.4;References;172
7.2;Particle Diffusion in Stably Stratified Flows;173
7.2.1;Introduction;173
7.2.2;Numerical Simulations and Results;174
7.2.3;References;176
7.3;Anisotropic Clustering of Inertial Particles in Shear Turbulence;177
7.3.1;Motivation and Results;177
7.3.2;References;180
7.4;Spatial Evolution of Inertial Particles in a Turbulent Pipe Flow;181
7.4.1;Instantaneous Visualization;181
7.4.2;Particles Concentration and Shannon Entropy;182
7.4.3;References;184
7.5;Direct Numerical Simulation of Particle Interaction with Coherent Structures in a Turbulent Channel Flow;185
7.5.1;Introduction;185
7.5.2;Results;186
7.5.3;Conclusions;187
7.5.4;References;188
8;Convection and Boundary Layer;12
8.1;Asymmetries in Turbulent Rayleigh-B\'{e}nard Convection;189
8.1.1;Introduction;189
8.1.2;Experimental Results;190
8.1.3;References;192
8.2;LES of Riblet Controlled Temporal Transition of Channel Flow;193
8.2.1;Introduction;193
8.2.2;Results;194
8.2.3;References;196
8.3;Evolution of a Boundary Layer from Laminar Stagnation-Point Flow towards Turbulent Separation;197
8.3.1;Motivation and Problem Formulation;197
8.3.2;Asymptotic Analysis;198
8.3.3;Numerical Results;199
8.3.4;Conclusions and Further Outlook;200
8.3.5;References;200
8.4;The Response of Wall Turbulence to Streamwise-Traveling Waves of Spanwise Velocity;201
8.4.1;Background;201
8.4.2;Numerical Details;202
8.4.3;Drag Reduction and Energy Savings;202
8.4.4;The Laminar Generalized Stokes Layer;203
8.4.5;References;204
8.5;Dynamics of ViscoelasticWall Turbulence in Different Ranges of Scales;205
8.5.1;Introduction;205
8.5.2;Small Scale Dynamics and Energy Containing Scales;206
8.5.3;Comments and Remarks;208
8.5.4;References;208
8.6;Hairpin Structures in a Turbulent Boundary Layer under Stalled-Airfoil-Type Flow Conditions;209
8.6.1;Introduction;209
8.6.2;Results and Discussion;210
8.6.3;References;212
8.7;Signature of VaricoseWave Packets in the Viscous Sublayer;213
8.7.1;Introduction;213
8.7.2;References;216
9;Special Flows;12
9.1;Entrainment Reduction and Additional Dissipation in Dilute Polymer Solutions;217
9.1.1;Introduction;217
9.1.2;Experimental Method;218
9.1.3;Results and Discussion;218
9.1.4;References;220
9.2;Mixing at the External Boundary of a Submerged Turbulent Jet;221
9.2.1;Experimental Set-Up;221
9.2.2;Theoretical Modelling of Turbulent Mixing and Comparison with Experiments;222
9.2.3;Conclusions;224
9.2.4;References;224
9.3;Turbulence in Electrically Conducting Fluids Driven by Rotating and Travelling Magnetic Fields;225
9.3.1;Introduction;225
9.3.2;Numerical Method;226
9.3.3;Results and Outlook;227
9.3.4;References;228
9.4;The Decay of Turbulence in Pipe Flow;229
9.4.1;Introduction;229
9.4.2;Lifetimes Results;230
9.4.3;References;232
9.5;The Effect of Spanwise System Rotation on Turbulent Poiseuille Flow at Very-Low-Reynolds Number;233
9.5.1;Introduction;233
9.5.2;Numerical Methods;234
9.5.3;Results and Discussion;234
9.5.4;Conclusions;236
9.5.5;References;236
9.6;LES of the Flow over a High-Lift Airfoil Configuration;237
9.6.1;Introduction;237
9.6.2;Numerical Method and Computational Setup;238
9.6.3;Results;238
9.6.4;References;239
9.7;The Effect of ObliqueWaves on Jet Turbulence;241
9.7.1;Introduction;241
9.7.2;Experimental Set-Up;242
9.7.3;Results, Discussion and Conclusions;243
9.7.4;References;244
9.8;Turbulence Enhancement in Coaxial Jet Flows by Means of Vortex Shedding;245
9.8.1;Introduction;245
9.8.2;Experimental Arrangement;246
9.8.3;Results;247
9.8.4;Conclusions;248
9.8.5;References;248
9.9;Direct Numerical Simulation of Microbubble Dispersion in Vertical Turbulent Channel Flow;249
9.9.1;Introduction;250
9.9.2;Results and Discussion;250
9.9.3;References;252
9.10;Experimental and Numerical Analysis of the Stability of the VerticalWater Jet with Rectangular Cross Section;253
9.10.1;Introduction;253
9.10.2;Experimental Set-Up;254
9.10.3;Measurement Results and Numerical Simulations;255
9.10.4;Conclusions;256
9.10.5;References;256
9.11;Control of Separated Flow Using an Oscillating Lorentz Force: Comparison of DNS, LES, and Experiments;257
9.11.1;Introduction;257
9.11.2;Setup;258
9.11.3;Results;258
9.11.4;References;260
9.12;Study of Effects of Wall-Normal Rotation on the Turbulent Channel Flow Using DNS;261
9.12.1;Introduction;261
9.12.2;DNS of Turbulent Wall-Normal Rotating Channel Flow;261
9.12.3;Conclusion;262
9.12.4;References;263
10;Vortex;13
10.1;A Langevin Equation for the Turbulent Vorticity;264
10.1.1;Kinetic Theory for the Turbulent Vorticity;264
10.1.2;Numerical Results;266
10.1.3;Discussion;267
10.1.4;References;267
10.2;Application of Helical Characteristics of the Velocity Field to Evaluate the Intensity of Tropical Cyclones;268
10.2.1;Brief History of the Problem;268
10.2.2;Helicity Flux as a Measure of Tropical Cyclone Intensity: Theoretical Ground;269
10.2.3;Calculations of Helicity Index for Tropical Cyclones;270
10.2.4;References;271
10.3;An Experimental Study of Turbulent Vortex Rings;272
10.3.1;Introduction;272
10.3.2;The Experiment;273
10.3.3;Results;273
10.3.3.1;Turbulence in and Around Core Area;273
10.3.3.2;Three Dimensional Structure Construction;275
10.3.4;Conclusion;275
10.3.5;References;275
11;Author Index;276