Download or read book Studies on the Hydrodynamic Interactions Between Two Drops Or Particles Moving in a Rarefied Gas written by Arvind Gopinath and published by . This book was released on 2001 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Hydrodynamic Interactions in Intermediate Reynolds Number Flows written by Açmae El Yacoubi and published by . This book was released on 2013 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collective behavior and self-organization are ubiquitous mechanisms in nature. From animate creatures, such as swarming insects, flocking birds and schooling fish, to inanimate natural processes such as sedimentation and cloud formation, these phenomena arouse the curiosity of physicists and engineers alike. Early studies using analytical models and experiments in the low Reynolds number helped shed the light on the intricacies of particle interactions, as in clouds or arrays of spheres. In the intermediate Reynolds number regime however, the unsteadiness introduced by the fluid inertia, coupled to the object dynamics, add to the complexity of the problem. Numerical methods become then the tool par excellence to solve for these dynamics. The goal of this thesis is to lay out the foundations for a better understanding of particle interactions in fluids. Namely, we investigate the two-dimensional dynamics of interacting particles in a viscous fluid, in the intermediate Reynolds number range. We develop a direct numerical scheme based on the Immersed Interface Method to simulate the coupling of the dynamics of freely moving objects with the surrounding fluid. The method is used to study the dynamics of arrays of cylinders settling under gravity, and how these dynamics depend on the number of particles and their initial separation. We then provide a simple force law model which accounts for the initial repulsive force experienced by any two adjacent cylinders, at close range. When the particle density is high, collisions are almost inevitable. To treat close range interactions and resolve the interstitial flow in the narrowing gap between particles or between a particle and a wall, we further extend the immersed interface method to take into account the lubrication effects. We solve Reynolds equations and use the analytical solution in the lubrication region. Doing so enables us to avoid ad hoc methods where an artificial repulsive force is added or two-dimensional collision equations are used with a modified coefficient of restitution.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1988 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Collective Hydrodynamics of Soft Microparticles in Quasi two dimensional Confinement written by William Eric Uspal and published by . This book was released on 2014 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow of microparticles through geometrically confined spaces is a core element of most microfluidic technologies. Flowing particles are typically ordered and manipulated with external forces or coflowing streams, but these methods can be limited in generality and scalability. New techniques to control particle trajectories would enable new applications in such areas as materials assembly, optofluidics, and miniaturized "on-chip" bioassays and cytometry. Recently, researchers have sought to understand the conditions under which particles can organize themselves through interactions generic to the flow of suspensions through microchannels. In particular, a particle moving through a viscous fluid will create a disturbance flow, affecting the motion of distant particles. These hydrodynamic interactions (HI) are sensitive to particle shape and the presence of confining boundaries. This sensitivity presents a powerful opportunity: particle trajectories could be "programmed" into particle morphology and channel design. These could chosen so that many-body hydrodynamic interactions drive self-organization of the desired particle motions. Even a single particle could be designed to "self-steer" to a desired position in the channel cross-section through its hydrodynamic self-interaction. In this thesis, we present a series of studies exploring new possibilities for achieving selforganization, self-steering, and other flow-driven collective phenomena via design of particle shape and channel geometry. We focus on a particular setting: quasi-two-dimensional (q2D) confinement, in which particles are tightly "sandwiched" between parallel plates, free to move in only two dimensions. In this confinement regime, hydrodynamic interactions take a unique dipolar form. This form had been shown to sustain novel collective phenomena with much greater spatiotemporal coherence than can be achieved in unconfined or weakly confined suspensions. However, self-organization of q2D suspensions had not been demonstrated prior to our studies. Starting from a two-body problem, we progressively consider larger numbers of particles and more complex particle shapes. In our first study, we develop model equations for the coupled motion of two discs in a quasi-two-dimensional channel. Numerically, we find that a pair can form a hydrodynamic bound state with complex oscillatory motion. We demonstrate that this "quasiparticle" can be manipulated via patterning of confining boundaries. In the following study, we consider larger clusters of discs. We provide symmetry principles for the a priori construction of "flowing crystals": configurations of particles that maintain their relative positions as they are carried by the flow. The crystalline states generalize the two-body bound state to more complex configurations and collective modes. We also consider the wider dynamical landscape, finding metastable states with new, exquisitely coordinated particle motions. However, neither flowing crystals nor metastable states spontaneously form from a disordered configuration of discs. In pursuit of self-steering and self-organization, we turn to particle shape, and study the dynamics of a single "dumbbell" comprising two connected discs. We find that a fore-aft asymmetric dumbbell will reliably align with the flow and focus to the channel centerline. In contrast, a symmetric particle will oscillate between the channel side walls indefinitely. Through theoretical arguments, we isolate three viscous hydrodynamic mechanisms that together produce self-steering, and which generically occur for asymmetric particles in q2D. We carry out experiments with Continuous Flow Lithography (CFL), finding qualitative and semi-quantitative agreement with our theoretical predictions. Obtaining statistics from hundreds of particle trajectories, we provide a convincing experimental demonstration of self-steering for device applications. To our knowledge, this study provides the first demonstration that rigid particles can focus to the centerline in a channel flow. This progression culminates in our final study. Inspired by the mobility formalism of polymer dynamics, we develop a theoretical and numerical framework that can recover the collective dynamics of many particles with complex shape. We find that small clusters of dumbbells can self-organize from disorder into one-dimensional flowing crystals. However, dumbbells can also pair as undesirable "defects." This two-body effect frustrates self-organization in large suspensions of dumbbells, driving formation of particle aggregates. To tame this aggregation, we rationally redesign particle shape, tailoring hydrodynamic interactions to promote chaining of particles in the flow direction. The redesigned "trumbbell" particles self-organize into large, two-dimensional flowing crystals. We reveal how crystal self-organization occurs through a multistage process. One, two, several, and finally many-body interactions become implicated in successive stages. This study is the first to demonstrate that flowing lattices can be stabilized purely by viscous hydrodynamic interactions.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bubbles Drops and Particles written by Roland Clift and published by Courier Corporation. This book was released on 2005-01-01 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a critical review of the literature concerning the fluid dynamics, heat transfer, and mass transfer of single bubbles, drops, and particles. Upper-level undergraduates and graduate students, as well as professionals in the fields of engineering, physics, chemistry, geophysics, and applied mathematics, will find it a unified treatment of solid particles, liquid drops, and gas bubbles. Starting with a summary of the fundamental principles and equations governing the behavior of bubbles, drops, and solid particles in Newtonian fluids, the text proceeds to a survey of the parameters used to characterize the shape of rigid particles, and of the factors that determine the shape of bubbles and drops. Succeeding chapters examine the behavior of solid and fluid particles under steady incompressible flow in an extended external phase. The text concludes with an exploration of effects that complicate the relatively simple case of a particle moving steadily through an unbounded fluid.
Download or read book Rarefied Gas Dynamics written by Felix Sharipov and published by John Wiley & Sons. This book was released on 2016-02-23 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aimed at both researchers and professionals who deal with this topic in their routine work, this introduction provides a coherent and rigorous access to the field including relevant methods for practical applications. No preceding knowledge of gas dynamics is assumed.
Download or read book Hydrodynamic Interactions Between Particles in Low Reynolds Number Flow A Modular Approach written by S. Kim and published by . This book was released on 1984 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modular method for calculating hydrodynamic interactions between particles in low-Reynolds-number flow has been constructed by using multipole expansion solutions for the reflection field. The approach is made possible by the use of Faxen laws in relating the multipole moment to the incident field. The method is illustrated and checked by recalculating known expressions for the resistance and mobility tensors for two spheres. The method can be readily generalized to handle three-particle (or n-particle) interactions as shown in a following paper. New forms of the Faxen laws for prolate spheroids are given and will form the basis for other papers on spheroid-spheroid and spheroid-wall hydrodynamic interactions. The important result is that first-reflection solutions can be readily calculated even in cases where the ambient velocity field is obtained by a numerical procedure. These results, as asymptotic (far-field) solutions, furnish a check for more robust codes. In addition, these are important on their own since these provide crucial information for te renormalization theory used in suspension rheology.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Russian Chemical Reviews written by and published by . This book was released on 2003 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gaseous Flow written by C. E. Normand and published by . This book was released on 1956 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adhesive Particle Flow written by Jeffery S. Marshall and published by Cambridge University Press. This book was released on 2014-03-31 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is targeted at professionals and graduate students working in disciplines where flow of adhesive particles plays a significant role.
Download or read book Flowing Matter written by Federico Toschi and published by Springer Nature. This book was released on 2019-09-25 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, published in the Soft and Biological Matter series, presents an introduction to selected research topics in the broad field of flowing matter, including the dynamics of fluids with a complex internal structure -from nematic fluids to soft glasses- as well as active matter and turbulent phenomena. Flowing matter is a subject at the crossroads between physics, mathematics, chemistry, engineering, biology and earth sciences, and relies on a multidisciplinary approach to describe the emergence of the macroscopic behaviours in a system from the coordinated dynamics of its microscopic constituents. Depending on the microscopic interactions, an assembly of molecules or of mesoscopic particles can flow like a simple Newtonian fluid, deform elastically like a solid or behave in a complex manner. When the internal constituents are active, as for biological entities, one generally observes complex large-scale collective motions. Phenomenology is further complicated by the invariable tendency of fluids to display chaos at the large scales or when stirred strongly enough. This volume presents several research topics that address these phenomena encompassing the traditional micro-, meso-, and macro-scales descriptions, and contributes to our understanding of the fundamentals of flowing matter. This book is the legacy of the COST Action MP1305 “Flowing Matter”.
Download or read book Rarefied Gas Dynamics written by Ching Shen and published by Springer Science & Business Media. This book was released on 2006-03-30 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamics is a science engaged in the investigation of the motion of air and other gases and their interaction with bodies, and is one of the most important bases of the aeronautic and astronautic techniques. The continuous improvement of the configurations of the airplanes and the space vehicles aid the constant enhancement of their performances are closely related with the development of the aerodynamics. In the design of new flying vehicles the aerodynamics will play more and more important role. The undertakings of aeronautics and astronautics in our country have gained achievements of world interest, the aerodynamics community has made outstanding contributions for the development of these undertakings and the science of aerodynamics. To promote further the development of the aerodynamics, meet the challenge in the new century, summary the experience, cultivate the professional personnel and to serve better the cause of aeronautics and astronautics and the national economy, the present Series of Modern Aerodynamics is organized and published.
Download or read book Monthly Index of Russian Accessions written by and published by . This book was released on 1969 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
