Progress in Wall Turbulence: Understanding and Modeling - Proceedings of the WALLTURB International Workshop held in Lille, France, April 21-23, 2009

Foreword

Preface

Acknowledgements

Contents

Contributors

The WALLTURB Project

Invited Speakers

The Law of the Wall. Indications from DNS, and Opinion

Classical Position

Mean Velocity

Other Quantities

Behavior of Turbulence Models

Alternative Analytical Proposals

Conflicting Experiments

Proposals of Non-uniqueness

Essence of the Proposals

Conceptual Consequences

A Situation with Log Laws and Erratic kappa Values

DNS Evidence

Logarithmic Law

Law of the Wall

Response to Pressure Gradients

Highlights

References

A Web-Services Accessible Turbulence Database and Application to A-Priori Testing of a Matrix Exponential Subgrid Model

Introduction: The Web-Accessible Public Turbulence Database

The Matrix Exponential Subgrid Model for LES

Database-Enabled A-Priori Tests

Conclusions

References

Modeling Multi-point Correlations in Wall-Bounded Turbulence

Introduction

Multi-point Correlations and LES

Modeling Anisotropy in Wall-Bounded Turbulence

Discussion

References

Theoretical Prediction of Turbulent Skin Friction on Geometrically Complex Surfaces

Introduction

Mathematical Formulation

Skin Friction Coefficient

Application of the Formula to Surface Riblets

Componential Contributions

Drag Reduction

Straight Riblets

Wavy Riblets

Conclusions

Appendix

References

Scaling Turbulent Fluctuations in Wall Layers

Introduction

Composite Expansions

Reynolds Shear Stress

Vorticity Fluctuations

Outer Vorticity

Inner Vertical Vorticity

Inner Spanwise Vorticity

Inner Streamwise Vorticity

Outer Vorticity and Dissipation

Normal Reynolds Stresses

Vertical Velocity Fluctuations

Streamwise Velocity Fluctuations

Spanwise Velocity Fluctuations

Summary

References

Session 1: The WALLTURB LML Experiment

The WALLTURB Joined Experiment to Assess the Large Scale Structures in a High Reynolds Number Turbulent Boundary Layer

Introduction

Experimental Setup

Samples results

Conclusions

References

Calibration of the WALLTURB Experiment Hot Wire Rake with Help of PIV

Introduction

Wires Location

Blockage Effect

Calibration

Conclusion

References

Spatial Correlation from the SPIV Database of the WALLTURB Experiment

Introduction

Experimental Setup

SPIV System

PIV Analysis

Spatial Correlation

2D Correlations

3D Correlations

Conclusion

References

Two-Point Correlations and POD Analysis of the WALLTURB Experiment Using the Hot-Wire Rake Database

Two-Point Correlations of WALLTURB Experiments

Proper Orthogonal Decomposition

Eigenvalue Distribution over POD Modes

Eigenvalue Distribution over POD and Spanwise Fourier Modes

Reconstruction of Velocity Field

Discussion and Summary

References

Session 2: Experiments in Flat Plate Boundary Layers

Reynolds Number Dependence of the Amplitude Modulated Near-Wall Cycle

Introduction

Quantifying Amplitude Modulation

Experiments

Variations with Reynolds Number

References

Tomographic Particle Image Velocimetry Measurements of a High Reynolds Number Turbulent Boundary Layer

Introduction

Experimental Procedure

Volume Reconstruction and PIV Processing

Results

Conclusion

References

Study of Vortical Structures in Turbulent Near-Wall Flows

Introduction

Description of the Database

Average Properties of the Database

Detection Technique

Results: Characteristics of the Vortices

Density of the Vortices

Radius of the Vortices

Vorticity of the Vortices

Conclusion

References

Session 3: Experiments in Adverse Pressure Gradient Boundary Layers

Two-Point Near-Wall Measurements of Velocity and Wall Shear Stress Beneath a Separating Turbulent Boundary Layer

Introduction

Measurement Techniques

Results

Mean Wall Shear Stress, Mean Velocity and Reynolds Stresses

Velocity-Wall-Shear-Stress Correlation

Time-Lag Correlations

References

Experimental Analysis of Turbulent Boundary Layer with Adverse Pressure Gradient Corresponding to Turbomachinery Conditions

Introduction

Experimental Setup and Measuring Techniques

Experimental Results and Scaling of TBL

Conclusion

References

Near Wall Measurements in a Separating Turbulent Boundary Layer with and without Passive Flow Control

Introduction

Experimental Apparatus and Methodology

Measurement Technique and Experiment Organization

Results and Discussion

Dissipation Mechanism

Three-Dimensional Effect of VGs

Conclusion

References

Session 4: Boundary Layer Structure and Scaling

On the Relationship Between Vortex Tubes and Sheets in Wall-Bounded Flows

Introduction

Statistical Analysis

Conditional Expected Fields

Conclusions

References

Spanwise Characteristics of Hairpin Packets in a Turbulent Boundary Layer Under a Strong Adverse Pressure Gradient

Introduction

Experimental Procedure

Results and Discussion

References

The Mesolayer and Reynolds Number Dependencies of Boundary Layer Turbulence

Historical Context

Spectra at Rtheta= 19,100

Summary and Conclusions

References

A New Wall Function for Near Wall Mixing Length Models Based on a Universal Representation of Near Wall Turbulence

Introduction

Vortices Properties in the TBL

Universal Representation

Wall Function Model

Channel Flow Validation

Conclusion

References

Session 5: DNS and LES

Direct Numerical Simulations of Converging-Diverging Channel Flow

Introduction

Description of the DNS

Results

Conclusions

References

Corrections to Taylor's Approximation from Computed Turbulent Convection Velocities

Introduction

The Estimation of the Convection Velocities

Spectral and Spatial Dependence of the Convection Velocity

The Effect of Taylor's Approximation

Conclusions

References

A Multi-scale & Dynamic Method for Spatially Evolving Flows

Introduction

Formulation of the Problem and Methodology

The Rescaling-Recycling Method: The Multi-scale Similarity Approach

Dynamic Approach

Results and Discussion

Conclusions

References

Statistics and Flow Structures in Couette-Poiseuille Flows

Introduction

Numerical Methodology

Mean and Fluctuating Properties

Turbulence Structure near the Moving Wall

Conclusions

References

Session 6: Theory

LES-Langevin Approach for Turbulent Channel Flow

Introduction

LES-Langevin Model for Wall Turbulence

Estimation of Stochastic Forcing in the Case of Channel Flow

A Priori Tests

The Filter and Spatial Resolution Dependence of the Stochastic Forcing and the Turbulent Force

Time Scale Separation

Results and Discussions

Conclusion

References

A Scale-Entropy Diffusion Equation for Wall Turbulence

Introduction

Scale-Entropy Diffusion Equation

Experimental Measurement of Structure Functions, Scaling Exponents and Intermittency Efficiency

Detection of Structures by a Thresholding Procedure of Velocity Fluctuations

The Notion of Equivalent Dispersion Scale

Conclusion

References

A Specific Behaviour of Adverse Pressure Gradient Near Wall Flows

Introduction

LML Experiment

LML Direct Numerical Simulation

Literature Data

Discussion

Conclusion

References

Session 7: RANS Modelling

A Nonlinear Eddy-Viscosity Model for Near-Wall Turbulence

Introduction

Mathematical Modeling

The Linear V2F Model

The Nonlinear V2F Model (NLV2F)

Results and Discussion

Experimental and Numerical Reference Data

Model Results and Discussion

Concluding Remarks

References

ASBM-BSL: An Easy Access to the Structure Based Model Technology

Introduction

ASBM Modelling

Coupling with a k - omega Model

Validation Results

Conclusions and Perspectives

References

Introduction of Wall Effects into Explicit Algebraic Stress Models Through Elliptic Blending

Introduction

Explicit Algebraic Methodology

Invariant and Functional Integrity Bases

Truncated Bases

Validation of the Models

Conclusions

References

Session 8: Dynamical Systems

POD Based Reduced-Order Model for Prescribing Turbulent Near Wall Unsteady Boundary Condition

Introduction

POD Analysis and Modelling Strategy

Flow Reconstruction and Coupling with LES

Low-Order Dynamical Systems

Conclusions and Perspectives

References

A POD-Based Model for the Turbulent Wall Layer

Introduction

Characteristics of the Direct Numerical Simulation

The Proper Orthogonal Decomposition

Derivation Hypotheses

Model Validation

Influence of the Calibration Procedure

Conclusion

References

HR SPIV for Dynamical System Construction

Introduction

Experimental Setup

HR SPIV System

PIV Analysis

Space-Time Correlations

Conclusion

References

The Stagnation Point Structure of Wall-Turbulence and the Law of the Wall in Turbulent Channel Flow

Introduction

Conventional Results of DNS of Turbulent Channel Flow

The Stagnation Point Approach

Consequences of the Constancies of B1 & Cs

Conclusion

References

Session 9: Large Eddy Simulation

Wall Modelling for Implicit Large Eddy Simulation of Favourable and Adverse Pressure Gradient Flows

Introduction

Numerical Method and Wall Modelling

Cut-Cell Finite-Volume IB Method

Wall Model on IB Boundary

Validation and Application

Validation for Turbulent Channel Flow

Application to Bump Flow

Conclusion

References

LES of Turbulent Channel Flow with Pressure Gradient Corresponding to Turbomachinery Conditions

Introduction

Numerical Procedure

Analysis of the Results

Conclusions

References

LES Modeling of Converging Diverging Turbulent Channel Flow

Introduction

Numerical Code

Subgrid-Scale Models

Test Case Description

Results

Conclusions

References

Large-Scale Organized Motion in Turbulent Pipe Flow

Introduction

Flow Facility, Experimental Setup, and PIV Processing

Discussion of First Results

Outlook

References

Session 10: Skin Friction

Near-Wall Measurements and Wall Shear Stress

Introduction

Very Near Wall Measurements Using LDA

Analysis of Bias in Near Wall Measurements

Momentum Integral Method

Conclusions

References

Measurements of Near Wall Velocity and Wall Stress in a Wall-Bounded Turbulent Flow Using Digital Holographic Microscopic PIV and Shear Stress Sensitive Film

Introduction

Wall Shear Stress Sensor

Sensor Calibration and Application

Experimental Setup

Results and Discussion

Velocity Profile Measurement

Conclusion

References

Friction Measurement in Zero and Adverse Pressure Gradient Boundary Layer Using Oil Droplet Interferometric Method

Introduction

Oil Film Interferometric Method

Oil Droplet Interferometric Method

Test Surface

Experimental Tests: ZPG and APG Cases

Conclusion

References

Session 11: Modified Wall Flow

Scaling of Turbulence Structures in Very-Rough-Wall Channel Flow

Introduction

Experimental Technique

Results and Discussion

Conclusions

References

Characterizing a Boundary Layer Flow for Bubble Drag Reduction

Review of Work on Drag Reduction by Air Bubbles

Preparation of a Zero Pressure Gradient Developing Boundary Layer

Outlook

References

Direct and Large Eddy Numerical Simulations of Turbulent Viscoelastic Drag Reduction

Direct Numerical Simulations (DNS)

DNS Model Equations

Numerical Method

DNS Results

Temporal Large Eddy Simulations (TLES)

TLES Model Equations

TLES Results at Retau0=180

References

DNS of Supercritical Carbon Dioxide Turbulent Channel Flow

Introduction

Numerical Method

Turbulence Statistics

Turbulent Kinetic Energy Budget

Heat Transfer Characteristics

Summary

References

Session 12: Industrial Modeling

Evaluation of v2-f and ASBM Turbulence Models for Transonic Aerofoil RAE2822

Introduction

Turbulence Model Selection and Test on Channel and Flat Plate

Results for RAE2822 Aerofoil

Conclusions

References

Turbulence Modelling Applied to Aerodynamic Design

Introduction

Reynolds Averaged Navier-Stokes Modelling

Reynolds Stress Modelling

LES/DES Modelling

Conclusions and Perspectives

References