Progress in Turbulence III: Proceedings of the Iti Conference in Turbulence 2008

ISBN-13: 9783642022241 / Angielski / Twarda / 2009 / 268 str.

Joachim Peinke; Martin Oberlack; Alessandro Talamelli

Opis

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.

Spis treści

Turbulence.- Fully Developed Turbulence with Diminishing Mean Vortex Stretching and Reduced Intermittency.- Spectral and Physical Forcing of Turbulence.- Fractal-Generated Turbulent Scaling Laws from a New Scaling Group of the Multi-Point Correlation Equation.- Investigation of the Conditional Scalar Dissipation Rate Across a Shear Layer Using Gradient Trajectories.- ‘Rational’ Turbulence Models?.- An Approximation of the Invariant Measure for the Stochastic Navier-Stokes.- Spatial Multi-Point Correlations in Inhomogeneous Turbulence.- Statistical Properties of Velocity Increments in Two-Dimensional Turbulence.- Enstrophy Transfers Study in Two-Dimensional Turbulence.- Two Point Velocity Difference Scaling along Scalar Gradient Trajectories in Turbulence.- Stochastic Analysis of Turbulence n-Scale Correlations in Regular and Fractal-Generated Turbulence.- Experimental Methods.- Holographic PIV with Low Coherent Light – Recent Progress in 3D Flow Measurements.- An Experimental Demonstration of Accelerated Tomo-PIV.- Using the 2D Laser-Cantilever-Anemometer for Two-Dimensional Measurements in Turbulent Flows.- 3D Structures from Stereoscopic PIV Measurements in a Turbulent Boundary Layer.- The Sphere Anemometer – A Fast Alternative to Cup Anemometry.- CICLoPE – A Large Pipe Facility for Detailed Turbulence Measurements at High Reynolds Number.- Wind Energy.- Aerodynamics of an Airfoil at Ultra-Low Reynolds Number.- Turbulence Energetics in Stably Stratified Atmospheric Flows.- Measurements of the Flow Upstream a Rotating Wind Turbine Model.- Is the Meandering of a Wind Turbine Wake Due to Atmospheric Length Scales?.- Impact of Atmospheric Turbulence on the Power Output of Wind Turbines.- About First Order Geometric Auto Regressive Processes for Boundary Layer Wind Speed Simulation.- Unsteady Numerical Simulation of the Turbulent Flow around a Wind Turbine.- A New Non-gaussian Turbulent Wind Field Generator to Estimate Design-Loads of Wind-Turbines.- Synthetic Turbulence Models for Wind Turbine Applications.- Numerical Simulation of the Flow around a Tall Finite Cylinder Using LES and PANS.- Large Eddy Simulation of Turbulent Flows around a Rotor Blade Segment Using a Spectral Element Method.- Modelling and Simulation and Mathematics.- Vorticity and Helicity in Swirling Pipe Flow.- Explicit Algebraic Subgrid Models for Large Eddy Simulation.- Direct Numerical Simulation of a Turbulent Flow with Pressure Gradients.- An Invariant Nonlinear Eddy Viscosity Model Based on a Consistent 4D Modelling Approach.- A Hybrid URANS/LES Approach Used for Simulations of Turbulent Flows.- Anisotropic Synthetic Turbulence with Sweeping Generated by Random Particle-Mesh Method.- LES and Hybrid LES/RANS Study of Flow and Heat Transfer around a Wall-Bounded Short Cylinder.- Stochastically Forced Laminar Plane Couette Flow: Non-normality and Hydrodynamic Fluctuations.- Reynolds Stress Model Based on the RDT Equations and Turbulence Dynamics in the Aerodynamic Nozzle.- Particle Laden Flows.- Heat Transfer Modulation by Microparticles in Turbulent Channel Flow.- Particle Diffusion in Stably Stratified Flows.- Anisotropic Clustering of Inertial Particles in Shear Turbulence.- Spatial Evolution of Inertial Particles in a Turbulent Pipe Flow.- Direct Numerical Simulation of Particle Interaction with Coherent Structures in a Turbulent Channel Flow.- Convection and Boundary Layer.- Asymmetries in Turbulent Rayleigh-Bénard Convection.- LES of Riblet Controlled Temporal Transition of Channel Flow.- Evolution of a Boundary Layer from Laminar Stagnation-Point Flow towards Turbulent Separation.- The Response of Wall Turbulence to Streamwise-Traveling Waves of Spanwise Velocity.- Dynamics of Viscoelastic Wall Turbulence in Different Ranges of Scales.- Hairpin Structures in a Turbulent Boundary Layer under Stalled-Airfoil-Type Flow Conditions.- Signature of Varicose Wave Packets in the Viscous Sublayer.- Special Flows.- Entrainment Reduction and Additional Dissipation in Dilute Polymer Solutions.- Mixing at the External Boundary of a Submerged Turbulent Jet.- Turbulence in Electrically Conducting Fluids Driven by Rotating and Travelling Magnetic Fields.- The Decay of Turbulence in Pipe Flow.- The Effect of Spanwise System Rotation on Turbulent Poiseuille Flow at Very-Low-Reynolds Number.- LES of the Flow over a High-Lift Airfoil Configuration.- The Effect of Oblique Waves on Jet Turbulence.- Turbulence Enhancement in Coaxial Jet Flows by Means of Vortex Shedding.- Direct Numerical Simulation of Microbubble Dispersion in Vertical Turbulent Channel Flow.- Experimental and Numerical Analysis of the Stability of the Vertical Water Jet with Rectangular Cross Section.- Control of Separated Flow Using an Oscillating Lorentz Force: Comparison of DNS, LES, and Experiments.- Study of Effects of Wall-Normal Rotation on the Turbulent Channel Flow Using DNS.- Vortex.- A Langevin Equation for the Turbulent Vorticity.- Application of Helical Characteristics of the Velocity Field to Evaluate the Intensity of Tropical Cyclones.- An Experimental Study of Turbulent Vortex Rings.

Blurb

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 sophisticated methods achieve more and more insights into the underlying complexity of turbulence. The increasing power of computational methods allows studying flows in more details. Increasing demands of high precision large turbulence experiments 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.

The structure of the present book is as such that contributions have been bundled according to covering topics i.e. I Turbulence, II Experimental Methods, III Wind Energy, IV Modeling & Simulation & Mathematics, V Particle Laden Flows, VI Convection & Boundary Layer, VII Special Flows and VIII Vortex.