Download or read book Dynamics of Non Spherical Particles in Turbulence written by Luis Blay Esteban and published by Springer. This book was released on 2019-08-13 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book studies the dynamics of 2D objects moving through turbulent fluids. It examines the decay of turbulence over extended time scales, and compares the dynamics of non-spherical particles moving through still and turbulent fluids. The book begins with an introduction to the project, its aims, and its relevance for industrial applications. It then discusses the movement of planar particles in quiescent fluid, and presents the numerous methodologies used to measure it. The book also presents a detailed analysis of the falling style of irregular particles, which makes it possible to estimate particle trajectory and wake morphology based on frontal geometry. In turn, the book provides the results of an analysis of physically constrained decaying turbulence in a laboratory setting. These results suggest that large-scale cut-off in numerical simulations can result in severe bias in the computed turbulent kinetic energy for long waiting times. Combining the main text with a wealth of figures and sketches throughout, the book offers an accessible guide for all engineering students with a basic grasp of fluid mechanics, while the key findings will also be of interest to senior researchers.

Download or read book Non spherical Particle Dynamics in Turbulence written by Stefan Kramel and published by . This book was released on 2017 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Collective Dynamics of Particles written by Cristian Marchioli and published by Springer. This book was released on 2017-02-21 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book surveys the state-of-the-art methods that are currently available to model and simulate the presence of rigid particles in a fluid flow. For particles that are very small relative to the characteristic flow scales and move without interaction with other particles, effective equations of motion for particle tracking are formulated and applied (e.g. in gas-solid flows). For larger particles, for particles in liquid-solid flows and for particles that interact with each other or possibly modify the overall flow detailed model are presented. Special attention is given to the description of the approximate force coupling method (FCM) as a more general treatment for small particles, and derivations in the context of low Reynolds numbers for the particle motion as well as application at finite Reynolds numbers are provided. Other topics discussed in the book are the relation to higher resolution immersed boundary methods, possible extensions to non-spherical particles and examples of applications of such methods to dispersed multiphase flows.

Download or read book The Rotation and Translation of Non spherical Particles in Homogeneous Isotropic Turbulence written by Margaret Byron and published by . This book was released on 2015 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: The motion of particles suspended in environmental turbulence is relevant to many scientific fields, from sediment transport to biological interactions to underwater robotics. At very small scales and simple shapes, we are able to completely mathematically describe the motion of inertial particles; however, the motion of large aspherical particles is significantly more complex, and current computational models are inadequate for large or highly-resolved domains. Therefore, we seek to experimentally investigate the coupling between freely suspended particles and ambient turbulence. A better understanding of this coupling will inform not only engineering and physics, but the interactions between small aquatic organisms and their environments. In the following pages, we explore the roles of shape and buoyancy on the motion of passive particles in turbulence, and allow these particles to serve as models for meso-scale aquatic organisms. We fabricate cylindrical and spheroidal particles and suspend them in homogeneous, isotropic turbulence that is generated via randomly-actuated jet arrays. The particles are fabricated with agarose hydrogel, which is refractive-index-matched to the surrounding fluid (water). Both the fluid and the particle are seeded with passive tracers, allowing us to perform Particle Image Velocimetry (PIV) simultaneously on the particle and fluid phase. To investigate the effects of shape, particles are fabricated at varying aspect ratios; to investigate the effects of buoyancy, particles are fabricated at varying specific gravities. Each particle type is freely suspended at a volume fraction of [Phi]=0.1%, for which four-way coupling interactions are negligible. The suspended particles are imaged together with the surrounding fluid and analyzed using stereoscopic PIV, which yields three velocity components in a two-dimensional measurement plane. Using image thresholding, the results are separated into simultaneous fluid-phase and solid-phase velocity fields. Using these simultaneous measurements, we examine particles' turbulent slip velocity and compare it to particles' quiescent settling velocity, which we measure directly. We observe that the slip velocity is strongly reduced relative to the quiescent case, and explore various mechanisms of particle loitering in turbulence. We further explore the relationship between the instantaneous particle velocity and the instantaneous fluid velocity, and develop a linear parametrization. By comparing our experimental data to a simple one-dimensional flow in the context of this parametrization, we elucidate aspects of slip velocity that are unique to turbulence. We obtain the particles' angular velocity by applying the solid-body rotation equation to velocity measurements at points inside the particle. We find that the expected value of angular velocity magnitude does not vary significantly with particle aspect ratio, as long as particles are nearly neutrally buoyant. Stronger effects on rotation are found for more negatively-buoyant particles. We also investigate particles' inheritance of vorticity from turbulent velocity fields, and find that particle rotation can be predicted by applying a spatial filter to fluid-phase vorticity. The results of this study will allow us to more accurately predict the motion of aspherical particles, giving new insights into oceanic carbon cycling, industrial processes, and other important topics. This analysis will also shed light onto biological questions of navigation, reproduction, and predator-prey interaction by quantifying the turbulence-driven behavior of meso-scale aquatic organisms, allowing researchers to sift out passive vs. active effects in a behaving organism. Lastly, processes that are directly dependent on particle dynamics (e.g., sediment transport, industrial processes) will be informed by our results.

Download or read book The Dynamics of Non spherical Particles 1 Controlled Generation of Non spherical Aerosols and Methods for Their Size Concentration and Electric Charge Measurement written by Isaiah Gallily and published by . This book was released on 1974 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: The typical features of the motion of a nonspherical aerosol particle are discussed, an overall aim concerning its behavior in systems of importance for human environment is stated and a preliminary objective of studying methods for generation, size measurement, determination of concentration and assessment of electric charge is set. Previous investigations in these lines are reviewed. Starting with model shapes, there were produced by solution spray-drying almost perfect cubes or parallelpipeds and, by suspension gas atomization, cylindrical particles of glass fibers. Dispersion of powders by air turbulence was treated theoretically and a computational investigation of the adhesional energy between two parallelpipeds at various mutual orientations begun. The size parameters of the produced particles were determined. A way of assessing the electric charge of a nonspherical particle is analyzed in view of the specificity of its motion and the relation to the principal translational resistances brought out. The effect of Brownian rotation on the translation of an aerosol particle was discussed. An apparatus for the determination of the principal resistances of a nonspherical particle at various Knudsen numbers has been constructed and a mathematical procedure for the elucidation of results developed.

Download or read book Modeling Approaches and Computational Methods for Particle laden Turbulent Flows written by Shankar Subramaniam and published by Academic Press. This book was released on 2022-10-20 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling Approaches and Computational Methods for Particle-laden Turbulent Flows introduces the principal phenomena observed in applications where turbulence in particle-laden flow is encountered while also analyzing the main methods for analyzing numerically. The book takes a practical approach, providing advice on how to select and apply the correct model or tool by drawing on the latest research. Sections provide scales of particle-laden turbulence and the principal analytical frameworks and computational approaches used to simulate particles in turbulent flow. Each chapter opens with a section on fundamental concepts and theory before describing the applications of the modelling approach or numerical method. Featuring explanations of key concepts, definitions, and fundamental physics and equations, as well as recent research advances and detailed simulation methods, this book is the ideal starting point for students new to this subject, as well as an essential reference for experienced researchers. Provides a comprehensive introduction to the phenomena of particle laden turbulent flow Explains a wide range of numerical methods, including Eulerian-Eulerian, Eulerian-Lagrange, and volume-filtered computation Describes a wide range of innovative applications of these models

Download or read book Turbulence Modulation by Non spherical Particles written by Matthias Mandø and published by . This book was released on 2009 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theoretical Approaches to Turbulence written by D.L. Dwoyer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence is the lIDst natural nDde of fluid lIDtion, and has been the subject of scientific study for all Dst a century. During this period, various ideas and techniques have evolved to nDdel turbulence. Following Saffman, these theoretical approaches can be broadly divided into four overlapping categories -- (1) analytical lIDdelling, (2) physical lIDdelling, (3) phenomenologicalllDdelling, and (4) nurerical lIDdelling. With the purpose of stmtnarizing our =ent understanding of these theoretical approaches to turbulence, recognized leaders (fluid dynamicists, mathematicians and physicists) in the field were invited to participate in a formal workshop during October 10-12, 1984, sponsored by The Institute for CooIputer Applications in Science and Engineering and NASA Langley Research Center. Kraiciman, McCcxnb, Pouquet and Spiegel represented the category of analytical nDdelling, while Landahl and Saffman represented physical lIDdelling. The contributions of Latmder and Spalding were in the category of phenanenological lIDdelling, and those of Ferziger and Reynolds in the area of nurericalllDdelling. Aref, Cholet, Lumley, Moin, Pope and Temam served on the panel discussions. With the care and cooperation of the participants, the workshop achieved its purpose, and we believe that its proceedings published in this vol\. llre has lasting scientific value. The tone of the workshop was set by two introductory talks by Bushnell and ChaImm. Buslmell presented the engineering viewpoint while Chapman reviewed from a historical perspective developments in the study of turbulence. The remaining talks dealt with specific aspects of the theoretical approaches to fluid turbulence.

Download or read book Particles in Wall Bounded Turbulent Flows Deposition Re Suspension and Agglomeration written by Jean-Pierre Minier and published by Springer. This book was released on 2016-07-26 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents an up-to-date review of turbulent two-phase flows with the dispersed phase, with an emphasis on the dynamics in the near-wall region. New insights to the flow physics are provided by direct numerical simuation and by fine experimental techniques. Also included are models of particle dynamics in wall-bounded turbulent flows, and a description of particle surface interactions including muti-layer deposition and re-suspension.

Download or read book Particle Dynamics in Turbulence written by Peter Dearborn Huck and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence is well known for its ability to efficiently disperse matter, whether it be atmospheric pollutants or gasoline in combustion motors. Two considerations are fundamental when considering such situations. First, the underlying flow may have a strong influence of the behavior of the dispersed particles. Second, the local concentration of particles may enhance or impede the transport properties of turbulence. This dissertation addresses these points separately through the experimental study of two different turbulent flows. The first experimental device used is the so-called von K\'arm\'an flow which consists of an enclosed vessel filled with water that is forced by two counter rotating disks creating a strongly inhomogeneous and anisotropic turbulence. Two high-speed cameras permitted the creation a trajectory data base particles that were both isodense and heavier than water but were smaller than the smallest turbulent scales. The trajectories of this data base permitted a study of the turbulent kinetic energy budget which was shown to directly related to the transport properties of the turbulent flow. The heavy particles illustrate the role of flow anisotropy in the dispersive dynamics of particles dominated by effects related to their inertia. The second flow studied was a wind tunnel seeded with micrometer sized water droplets which was used to study the effects of local concentration of the settling velocities of these particles. A model based on theoretical multi-phase methods was developed in order to take into account the role of collective effects on sedimentation in a turbulent flow. The theoretical results emphasize the role of coupling between the underlying flow and the dispersed phase.

Download or read book Computational Fluid Dynamics written by T. J. Chung and published by Cambridge University Press. This book was released on 2010-09-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of Computational Fluid Dynamics represents a significant improvement from the first edition. However, the original idea of including all computational fluid dynamics methods (FDM, FEM, FVM); all mesh generation schemes; and physical applications to turbulence, combustion, acoustics, radiative heat transfer, multiphase flow, electromagnetic flow, and general relativity is still maintained. The second edition includes a new section on preconditioning for EBE-GMRES and a complete revision of the section on flowfield-dependent variation methods, which demonstrates more detailed computational processes and includes additional example problems. For those instructors desiring a textbook that contains homework assignments, a variety of problems for FDM, FEM and FVM are included in an appendix. To facilitate students and practitioners intending to develop a large-scale computer code, an example of FORTRAN code capable of solving compressible, incompressible, viscous, inviscid, 1D, 2D and 3D for all speed regimes using the flowfield-dependent variation method is made available.

Download or read book Measurement of Non continuum and Turbulence Effects on Subsonic Sphere Drag written by Neil Arthur Zarin and published by . This book was released on 1970 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Direct and Large Eddy Simulation XII written by Manuel García-Villalba and published by Springer Nature. This book was released on 2020-05-09 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the proceedings of the 12th instalment in the bi-annual Workshop series on Direct and Large Eddy Simulation (DLES), which began in 1994 and focuses on modern techniques used to simulate turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structure. With the rapidly expanding capacities of modern computers, this approach has attracted more and more interest over the years and will undoubtedly be further enhanced and applied in the future. Hybrid modelling techniques based on a combination of LES and RANS approaches also fall into this category and are covered as well. The goal of the Workshop was to share the state of the art in DNS, LES and related techniques for the computation and modelling of turbulent and transitional flows. The respective papers highlight the latest advances in the prediction, understanding and control of turbulent flows in academic and industrial applications.

Download or read book Turbulence and Interactions written by Michel Deville and published by Springer Nature. This book was released on 2021-02-16 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a snapshot of the state-of-art in the field of turbulence modeling, with an emphasis on numerical methods. Topics include direct numerical simulations, large eddy simulations, compressible turbulence, coherent structures, two-phase flow simulation and many more. It includes both theoretical contributions and experimental works, as well as chapters derived from keynote lectures, presented at the fifth Turbulence and Interactions Conference (TI 2018), which was held on June 25-29 in Martinique, France. This multifaceted collection, which reflects the conference ́s emphasis on the interplay of theory, experiments and computing in the process of understanding and predicting the physics of complex flows and solving related engineering problems, offers a timely guide for students, researchers and professionals in the field of applied computational fluid dynamics, turbulence modeling and related areas.

Download or read book Advances in Mechanics of Materials and Structural Analysis written by Holm Altenbach and published by Springer. This book was released on 2018-01-04 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a collection of contributions on the advanced mechanics of materials and mechanics of structures approaches, written in honor of Professor Kienzler. It covers various topics related to constitutive models for advanced materials, recent developments in mechanics of configuration forces, as well as new approaches to the efficient modeling and analysis of engineering structures.

Download or read book Turbulence and Interactions written by Michel Deville and published by Springer. This book was released on 2014-10-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keynote Lectures.- Some Characteristics of Non-Reacting and Reacting Low Swirl Number Jets.- Inner-Outer Interactions in Wall-Bounded Turbulence.- Turbulence Interaction with Atmospheric Physical Processes.- LES of Pulsating Turbulent Flows over Smooth and Wavy Boundaries.- Numerical Study of Turbulence-Wave Interaction.- High Reynolds Number Wall-Bounded Turbulence and a Proposal for a New Eddy-Based Model.- Regular Papers.- PANS Methodology Applied to Elliptic-Relaxation Based Eddy Viscosity Transport Model.- PIV Study of Turbulent Flow in Porous Media.- A Model for Dissipation: Cascade SDE with Markov Regime-Switching and Dirichlet Prior.- Wavelet Analysis of the Turbulent LES Data of the Lid-Driven Cavity Flow.- A Two-Phase LES Compressible Model for Plasma-Liquid Jet Interaction.- Simulation of a Fluidized Bed Using a Hybrid Eulerian-Lagrangian Method for Particle Tracking.- Wavelet-Adapted Sub-grid Scale Models for LES.- Effect of Particle-Particle Collisions on the Spatial Distribution of Inertial Particles Suspended in Homogeneous Isotropic Turbulent Flows.- Effect of Near-Wall Componental Modification of Turbulence on Its Statistical Properties.- Large-Eddy Simulation of Transonic Buffet over a Supercritical Airfoil.- Large Eddy Simulation of Coherent Structures over Forest Canopy.- Toroidal/Poloidal Modes Dynamics in Anisotropic Turbulence.- Grid Filter Modeling for Large-Eddy Simulation.- Pulsating Flow through Porous Media.- Thermodynamic Fluctuations Behaviour during a Sheared Turbulence/Shock Interaction.- LES and DES Study of Fluid-Particle Dynamics in a Human Mouth-Throat Geometry.- Viscous Drag Reduction with Surface-Embedded Grooves.- Study on the Resolution Requirements for DNS in Turbulent Rayleigh-Bénard Convection.- On the Role of Coherent Structures in a Lid Driven Cavity Flow.- Local versus Nonlocal Processes in Turbulent Flows, Kinematic Coupling and General Stochastic Processes.- Time-Resolved 3D Simulation of an Aircraft Wing with Deployed High-Lift System.- Fluid Mechanics and Heat Transfer in a Channel with Spherical and Oval Dimples.- Investigation of the Flow around a Cylinder Plate Configuration with Respect to Aerodynamic Noise Generation Mechanisms.- LES of the Flow around Ahmed Body with Active Flow Control.- Enhanced Bubble Migration in Turbulent Channel Flow by an Acceleration-Dependent Drag Coefficient.- Experimental and Numerical Study of Unsteadiness in Boundary Layer / Shock Wave Interaction.- Measurement of Particle Accelerations with the Laser Doppler Technique.- A Novel Numerical Method for Turbulent, Two-Phase Flow.- Modeling of High Reynolds Number Flows with Solid Body Rotation or Magnetic Fields.- Direct Numerical Simulation of Buoyancy Driven Turbulence inside a Cubic Cavity.- Numerical Simulations of a Massively Separated Reactive Flow Using a DDES Approach for Turbulence Modelling.- Particle Dispersion in Large-Eddy Simulations: Influence of Reynolds Number and of Subgrid Velocity Deconvolution.- Use of Lagrangian Statistics for the Direct Analysis of the Turbulent Constitutive Equation.- Numerical Simulation of Supersonic Jet Noise with Overset Grid Techniques.- Large Eddy Simulation of Turbulent Jet Flow in Gas Turbine Combustors.- Computations of the Flow around a Wind Turbine: Grid Sensitivity Study and the Influence of Inlet Conditions.- Stochastic Synchronization of the Wall Turbulence.- Large-Eddy Simulations of an Oblique Shock Impinging on a Turbulent Boundary Layer: Effect of the Spanwise Confinement on the Low-Frequency Oscillations.- Parameter-Free Symmetry-Preserving Regularization Modelling of Turbulent Natural Convection Flows.- An a Priori Study for the Modeling of Subgrid Terms in Multiphase Flows.- Computation of Flow in a 3D Diffuser Using a Two-Velocity Field Hybrid RANS/LES.- On the Dynamics of High Reynolds Number Turbulent Axisymmetric and Plane Separating/Reattaching Flows.- Numerical Simulation and Statistical Modeling of Inertial Droplet Coalescence

Download or read book Fluid Dynamics of Particles Drops and Bubbles written by Eric Loth and published by Cambridge University Press. This book was released on 2023-06-30 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modern presentation of multiphase flow, from basic principles to state-of-the-art research. Explains dispersed fluid dynamics for bubbles, drops, or solid particles, incorporating detailed theory, experiments, simulations, and models while considering applications and recent cutting-edge advances. The book demonstrates the importance of multiphase flow in engineering and natural systems, considering particle size distributions, shapes and trajectories as well as deformation of fluid particles and multiphase flow numerical methods. The scope of the book also includes coupling physics between particles and turbulence through dispersion and modulation, and specific phenomena such as gravitational settling and collisions for solid particles, drops and bubbles. Featuring over eighty homework problems for each of the primary chapters, including theory-based and engineering application questions. The comprehensive coverage will give the reader a solid grounding for multiphase flow research and design, applicable to current and future engineering. This is an ideal resource for graduate students, researchers and professionals.