Experimental Investigations Into the Transitions to Turbulence in Newtonian and Drag-reducing Polymeric Taylor-Couette Flows

Experimental Investigations Into the Transitions to Turbulence in Newtonian and Drag-reducing Polymeric Taylor-Couette Flows PDF Author: Cari Suzanne Dutcher
Publisher:
ISBN:
Category :
Languages : en
Pages : 586

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Experimental Investigations Into the Transitions to Turbulence in Newtonian and Drag-reducing Polymeric Taylor-Couette Flows

Experimental Investigations Into the Transitions to Turbulence in Newtonian and Drag-reducing Polymeric Taylor-Couette Flows PDF Author: Cari Suzanne Dutcher
Publisher:
ISBN:
Category :
Languages : en
Pages : 586

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Transition and Turbulence

Transition and Turbulence PDF Author: Richard E. Meyer
Publisher: Academic Press
ISBN: 1483264599
Category : Technology & Engineering
Languages : en
Pages : 257

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Book Description
Mathematics Research Center Symposia and Advanced Seminar Series: Transition and Turbulence covers the lectures presented at the Symposium on Transition and Turbulence in Fluids, held in Madison, Wisconsin on October 13-15, 1980 under the auspices of the Mathematics Research Center of the University of Wisconsin-Madison. The book focuses on the relation between transition and turbulence in fluids and the importance of this relation for the understanding of many real fluid motions. The selection first elaborates on transition in flow between rotating concentric cylinders, observations in the Taylor experiment, and transition to turbulence in thermal convection with and without rotation. Discussions focus on low aspect ratio convection layers, random convection in a rotating layer, unsteady flows at high Reynolds numbers, transition to oscillatory motion, and experimental observations. The text then tackles instability and turbulence in jets, instability and transition in pipes and channels, and transition to turbulence in boundary layers. The book ponders on coherent structures in turbulence; interactions between large-scale coherent structures and fine-grained turbulence in free shear flows; and vortex interactions and coherent structures in turbulence. Topics include atomic and molecular representations, vortices in uniform strain, vortex pairs, numerical computations applied to a simple problem, agglomeration of large-scale structures and subharmonic formation, retrieving phase information, and dynamical equations. The selection is highly recommended for researchers interested in pursuing further studies on transition and turbulence.

Nonlinear Waves and Pattern Dynamics

Nonlinear Waves and Pattern Dynamics PDF Author: Nizar Abcha
Publisher: Springer
ISBN: 3319781936
Category : Science
Languages : en
Pages : 238

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Book Description
This book addresses the fascinating phenomena associated with nonlinear waves and spatio-temporal patterns. These appear almost everywhere in nature from sand bed forms to brain patterns, and yet their understanding still presents fundamental scientific challenges. The reader will learn here, in particular, about the current state-of-the art and new results in: Nonlinear water waves: resonance, solitons, focusing, Bose-Einstein condensation, as well as and their relevance for the sea environment (sea-wind interaction, sand bed forms, fiber clustering) Pattern formation in non-equilibrium media: soap films, chimera patterns in oscillating media, viscoelastic Couette-Taylor flow, flow in the wake behind a heated cylinder, other pattern formation. The editors and authors dedicate this book to the memory of Alexander Ezersky, Professor of Fluid Mechanics at the University of Caen Normandie (France) from September 2007 to July 2016. Before 2007, he had served as a Senior Scientist at the Institute of Applied Physics of the Russian Academy of Sciences in Nizhny Novgorod (Russia). The chapters have been written by leading scientists in Nonlinear Physics, and the topics chosen so as to cover all the fields to which Prof. Ezersky himself contributed, by means of experimental, theoretical and numerical approaches. The volume will appeal to advanced students and researchers studying nonlinear waves and pattern dynamics, as well as other scientists interested in their applications in various natural media.

A Review of Approaches to the Study of Turbulence Modification by Means of Non-Newtonian Additives

A Review of Approaches to the Study of Turbulence Modification by Means of Non-Newtonian Additives PDF Author: Dimitris Vlassopoulos
Publisher:
ISBN:
Category :
Languages : en
Pages : 130

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Book Description
The addition of small amounts of polymers to Newtonian liquids under conditions of turbulent flow results in substantial reduction of skin friction. This phenomenon has been observed experimentally. It can be attributed to the unusual behavior of dilute polymer solutions in turbulent flows. A condensed review of topics relevent to theoretical study of drag reduction by non-Newtonian additives is presented. In addition, the techniques and results of experimental investigations of this phenomenon are examined. It is proposed that dilute solutions of polymers or surfactants can be rheologically characterized by measuring the secondary flow characteristics that occur in the neighborhood of an oscillating cylinder. Plans for conducting these measurements are presented. Keywords: Drag reduction; Turbulence modifications; Rheology; Non-Newtonian fluid mechanics; Viscoelastic liquids; Polymers; Surfactants.

Advances in Turbulence XII

Advances in Turbulence XII PDF Author: Bruno Eckhardt
Publisher: Springer
ISBN: 9783662519325
Category : Science
Languages : en
Pages : 0

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Book Description
Lagrangian aspects.- Lagrangian modeling and properties of particles with inertia.- Effect of Faxén forces on acceleration statistics of material particles in turbulent flow.- Lagrangian analysis of turbulent convection.- Linear and angular dynamics of an inertial particle in turbulence.- Collision rate between heavy particles in a model turbulent flow.- From cloud condensation nuclei to cloud droplets: a turbulent model.- Lagrangian statistics of inertial particles in turbulent flow.- Lagrangian statistics of two–dimensional turbulence in a square container.- Measurement of Lagrangian Particle Trajectories by Digital in-line Holography.- 3-D Particle Tracking Velocimetry (PTV) in gas flows using coloured tracer particles.- Two-particle dispersion in 2D inverse cascade turbulence and its telegraph equation model.- Numerical simulations of particle dispersion in stratified flows.- Instability and Transition.- Experimental study of the von Kármán flow from = 10 to 10: spontaneous symmetry breaking and turbulent bifurcations.- Flow reversals in a vertical channel.- Linear Instability of Streamwise Corner Flow.- DNS of turbulent plane Couette flow with emphasis on turbulent stripe.- Geometry of state space in plane Couette flow.- Linear and nonlinear instabilities of sliding Couette flow.- Localization in plane Couette edge dynamics.- Nonlinear optimal perturbations in plane Couette flow.- Order parameter in laminar-turbulent patterns.- Pattern formation in low Reynolds number plane Couette flow.- Quasi-stationary and chaotic convection in low rotating spherical shells.- Linear stability of 2D rough channels.- Transient turbulent bursting in enclosed flows.- On New Localized Vortex Solutions in the Couette-Ekman Layer.- Shear instabilities in Taylor-Couette flow.- Particle Tracking Velocimetry in Transitional Plane Couette Flow.- Experimental study of coherent structures in turbulent pipe flow.- Forced localized turbulence in pipe flows.- From localized to expanding turbulence.- Influence of test-rigs on the laminar-to-turbulent transition of pipe flows.- Interaction of turbulent spots in pipe flow.- Large-scale transitional dynamics in pipe flow.- Nonlinear coherent structures in a square duct.- Quantitative measurement of the life time of turbulence in pipe flow.- Experimental investigation of turbulent patch evolution in spatially steady boundary layers.- Interaction of noise disturbances and streamwise streaks.- Linear generation of multiple time scales by 3D unstable perturbations.- Convection at very high Rayleigh number: signature of transition from a micro-thermometer inside the flow.- Estimating local instabilities for irregular flows in the differentially heated rotating annulus.- Search for the “ultimate state” in turbulent Rayleigh-Bénard convection.- Rayleigh–Taylor instability in two dimensions and phase-field method.- Split energy cascade in quasi-2D turbulence.- Stabililty and laminarisation of turbulent rotating channel flow.- The vortical flow pattern exhibited by the channel flow on a rotating system just past transition under the influence of the Coriolis force.- Transient evolution and high stratification scaling in horizontal mixing layers.- Control of turbulent flows.- Toward cost-effective Control of Wall Turbulence for Skin Friction Drag Reduction.- Active control of turbulent boundary layer using an array of piezo-ceramic actuators.- Flat plate turbulent boundary-layer control using vertical LEBUs.- Estimation of the spanwise wall shear stress based on upstream information for wall turbulence control.- Interactions between vortex generators and a flat plate boundary layer. Application to the control of separated flows..- Modulated global mode of a controlled wake.- Swirl effects in turbulent pipe flow.- Control of an axisymmetric turbulent wake by a pulsed jet.- Direct Numerical Simulations of turbulent mixed convection in enclosures with heated obstacles.-

Drag Reduction of Turbulent Flows by Additives

Drag Reduction of Turbulent Flows by Additives PDF Author: A. Gyr
Publisher: Springer Science & Business Media
ISBN: 9401712956
Category : Technology & Engineering
Languages : en
Pages : 243

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Book Description
Drag Reduction of Turbulent Flows by Additives is the first treatment of the subject in book form. The treatment is extremely broad, ranging from physicochemical to hydromechanical aspects. The book shows how fibres, polymer molecules or surfactants at very dilute concentrations can reduce the drag of turbulent flow, leading to energy savings. The dilute solutions are considered in terms of the physical chemistry and rheology, and the properties of turbulent flows are presented in sufficient detail to explain the various interaction mechanisms. Audience: Those active in fundamental research on turbulence and those seeking to apply the effects described. Fluid mechanical engineers, rheologists, those interested in energy saving methods, or in any other application in which the flow rate in turbulent flow should be increased.

Applied Mechanics Reviews

Applied Mechanics Reviews PDF Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 742

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An Experimental Investigation on Turbulent Plane Couette Flow in Dilute Polymer Solutions

An Experimental Investigation on Turbulent Plane Couette Flow in Dilute Polymer Solutions PDF Author: S. H. Chue
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Structure of Turbulence and Drag Reduction

Structure of Turbulence and Drag Reduction PDF Author: Albert Gyr
Publisher: Springer Science & Business Media
ISBN: 3642509711
Category : Science
Languages : en
Pages : 617

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Book Description
In 1976 a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington . However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and by direct manipulation of the walls (compliant walls and heated surfaces) were discussed. In the meantime it became evident that drag reduction also occurs when turbulence is influenced by geometrical means, e.g. by influencing the pressure distribution by the shape of the body (airfoils) or by the introduction of streamwise perturbances on a body (riblets). In the recent years turbulence research has seen increasing attention being focused on the investigation of coherent structures, mainly in Newtonian fluids. We all know that these structures are a significant feature of turbulent flows, playing an important role in the energy balance in such flows. However their place in turbulence theories as weil as the factors influencing their development are still poorly understood. Consequently, the investigation of phenomena in which the properties of coherent structures are alte red provides a promising means of improving our understanding of turbulent flows in general.

Transition and Turbulence Control

Transition and Turbulence Control PDF Author: Mohamed Gad-el-Hak
Publisher: World Scientific
ISBN: 9812700897
Category : Science
Languages : en
Pages : 445

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Book Description
This volume contains articles based on lectures given at the Workshop on Transition and Turbulence Control, hosted by the Institute for Mathematical Sciences, National University of Singapore, 8OCo10 December 2004. The lecturers included 13 of the worldOCOs foremost experts in the control of transitioning and turbulent flows. The chapters cover a wide range of subjects in the broad area of flow control, and will be useful to researchers working in this area in academia, government laboratories and industry. The coverage includes control theory, passive, active and reactive methods for controlling transitional and turbulent wall-bounded flows, noise suppression and mixing enhancement of supersonic turbulent jets, compliant coatings, modern flow diagnostic systems, and swept wing instabilities."