Download or read book Bifurcating and Blooming Jets written by Mario Lee and published by . This book was released on 1985 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Control of Structure in Turbulent Flows Bifurcating and Blooming Jets written by W. C. Reynolds and published by . This book was released on 1987 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: The general objective of this work is to control jet flows by properly organizing the dominant large-scale vortex structures. The work has focused on understanding the influence of excitation frequency and amplitude on the large-scale structures of these flows at various Reynolds numbers. Specifically, the effects of dual-mode forcing on the structure, momentum, and mixing characteristics of turbulent jets have been investigated using a combination of laboratory experiments and numerical simulations. The combination of properly-selected axial and orbital excitation has been shown to have dramatic effect on the structure and mixing of round jets. Experiments and numerical simulations show that these phenomena are due to interaction between the large-scale vortices in the jet near field. The position and phasing of these vortices can be altered by relatively weak excitation, causing the jet to divide into two separate jets (bifurcation) or to explode (bloom) in a shower of vortex rings. This report summarizes the key results of studies in water and low-speed air flows.
Download or read book Bifurcating Jets at High Reynolds Numbers written by D. E. Parekh and published by . This book was released on 1988 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is much interest in the use of controlled excitations to manage various types of flows. This work focuses on use of dual-mode forcing to alter dramatically the structure of round turbulent jets. Properly-combined axial and helical excitations can cause a round jet to split into two distinct jets. This Y-shaped jet, known as a bifurcating jet, exhibits spreading angles as high as 80 deg. Vortex rings are formed at the jet exit and propagate along the two branches of the jet. A vortex-filament code was developed for simulating the large-scale features of bifurcating jets. The motion and interaction of the vortex structures in this flow are tracked in a three-dimensional, Lagrangian coordinate system. This simulation showed that inviscid vortex interactions cause the dramatic changes in jet development and that spreading angle increases with axial Strouhal number. The experimental apparatus consists of an acoustically-excited, 2-cm-diameter air jet. The jet evolution is documented by flow visualization at velocities up to 75 m/s, Reynolds numbers up to 100,000, and Mach numbers up to 0.22. Instantaneous and phase-average cross-sections of the jet reveal the effects of forcing amplitude on the structure and spreading angle of axially-excited, helically-excited, and bifurcating jets. The primary conclusions of this experiment are that: 1) Dual-mode acoustic excitation can produce bifurcation in air jets at high Reynolds numbers and that the jet spreading angle increases with both excitation amplitudes; and 2) The excitation amplitude required to produce bifurcation increases with Reynolds number, but the corresponding excitation Strouhal number is invariant. (EDC).
Download or read book Synthetic Jets written by Kamran Mohseni and published by CRC Press. This book was released on 2014-09-17 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiles Information from a Multitude of SourcesSynthetic jets have been used in numerous applications, and are part of an emergent field. Accumulating information from hundreds of journal articles and conference papers, Synthetic Jets: Fundamentals and Applications brings together in one book the fundamentals and applications of fluidic actuators.
Download or read book Incompressible Flow written by Ronald L. Panton and published by John Wiley & Sons. This book was released on 2024-03-19 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt: Incompressible Flow The latest edition of the classic introduction to fluid dynamics This textbook offers a detailed study of fluid dynamics. Equal emphasis is given to physical concepts, mathematical methods, and illustrative flow patterns. The book begins with a precise and careful formulation of physical concepts followed by derivations of the laws governing the motion of an arbitrary fluid, the Navier-Stokes equations. Throughout, there is an emphasis on scaling variables and dimensional analysis. Incompressible flow is presented as an asymptotic expansion of solutions to the Navier-Stokes equations with low Mach numbers and arbitrary Reynolds numbers. The different physical behaviors of flows with low, medium, and high Reynolds number are thoroughly investigated. Additionally, several special introductory chapters are provided on lubrication theory, flow stability, and turbulence. In the Fifth Edition, a chapter on gas dynamics has been added. Gas dynamics is presented as Navier-Stokes solutions for high Reynolds Number at arbitrary Mach number with a perfect gas as the fluid. The existence of several excellent, and free, compressible flow calculators on the internet has been used in the presentation and the homework. With this chapter the textbook becomes a survey of the entire field of fluid dynamics. Readers of the Fifth Edition of Incompressible Flow will also find: New content treating wind turbines Examples and end-of-chapter problems to reinforce learning MATLAB codes available for download Incompressible Flow is ideal for undergraduate and graduate students in advanced fluid mechanics classes, and for any engineer or researcher studying fluid dynamics or related subjects.
Download or read book Separated Flows and Jets written by Victor V. Kozlov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 907 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separated flows and jets are closely linked in a variety of applications. They are of great importance in various fields of fluid mechanics including vehicle efficiency, technical branches concerned with gas/liquid flows, atmospheric effects on various constructions, etc. Knowledge of the physics of separated flows and jets and the development of reliable control techniques are prerequisite for future progress in the field. These aspects were in focus during the IUTAM-Symposium which was held in Novosibirsk, 9-13 July, 1990. This volume contains a selection of papers presenting recent results of theoretical and numerical studies as well as experimental work on separated flows and jets. The topics include sub- and supersonic, laminar and turbulent separation as well as organized structures in separated flows and jets. The reader will find here the state of the art and major trends for research in this field of aero-hydrodynamics.
Download or read book Direct and Large Eddy Simulation VI written by E. Lamballais and published by Springer Science & Business Media. This book was released on 2006-10-19 with total page 783 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sixth ERCOFTAC Workshop on ‘Direct and Large-Eddy Simulation’ (DLES-6) was held at the University of Poitiers from September 12-14, 2005. Following the tradition of previous workshops in the DLES-series, this edition has reflected the state-of-the-art of numerical simulation of transitional and turbulent flows and provided an active forum for discussion of recent developments in simulation techniques and understanding of flow physics.
Download or read book Mixing and Combustion of Pulsed Gas Jets written by and published by . This book was released on 1988 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Control written by Thomas C. Corke and published by Cambridge University Press. This book was released on 2024-04-11 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive treatment of passive and active flow control in fluid dynamics, with an emphasis on utilizing fluid instabilities for enhancing control performance. Examples are given from a wide range of technologically important flow fields occurring in aerospace applications, from low-subsonic to hypersonic Mach numbers. This essential book can be used for both research and teaching on the topics of fluid instabilities, fluid measurement and flow actuator techniques, and problem sets are provided at the end of each chapter to reinforce key concepts and further extend readers' understanding of the field. The solutions manual is available as a online resource for instructors. The text is well suited for both graduate students in fluid dynamics and for practising engineers in the aerodynamics design field.
Download or read book Unsteady Combustor Physics written by Tim C. Lieuwen and published by Cambridge University Press. This book was released on 2012-08-27 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with unsteady combustor issues, which have posed key challenges associated with development of clean, high-efficiency combustion systems.
Download or read book Micro and Nanoflows written by Valery Ya. Rudyak and published by Springer. This book was released on 2018-04-18 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes physical, mathematical and experimental methods to model flows in micro- and nanofluidic devices. It takes in consideration flows in channels with a characteristic size between several hundreds of micrometers to several nanometers. Methods based on solving kinetic equations, coupled kinetic-hydrodynamic description, and molecular dynamics method are used. Based on detailed measurements of pressure distributions along the straight and bent microchannels, the hydraulic resistance coefficients are refined. Flows of disperse fluids (including disperse nanofluids) are considered in detail. Results of hydrodynamic modeling of the simplest micromixers are reported. Mixing of fluids in a Y-type and T-type micromixers is considered. The authors present a systematic study of jet flows, jets structure and laminar-turbulent transition. The influence of sound on the microjet structure is considered. New phenomena associated with turbulization and relaminarization of the mixing layer of microjets are discussed. Based on the conducted experimental investigations, the authors propose a chart of microjet flow regimes. When addressing the modeling of microflows of nanofluids, the authors show where conventional hydrodynamic approaches can be applied and where more complicated models are needed, and they analyze the hydrodynamic stability of the nanofluid flows. The last part of the book is devoted the statistical theory of the transport processes in fluids under confined conditions. The authors present the constitutive relations and the formulas for transport coefficients. In conclusion the authors present a rigorous analysis of the viscosity and diffusion in nanochannels and in porous media.
Download or read book Transition Turbulence and Combustion Modelling written by A. Hanifi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: This single-volume work gives an introduction to the fields of transition, turbulence, and combustion modeling of compressible flows and provides the physical background for today’s modeling approaches in these fields. It presents basic equations and discusses fundamental aspects of hydrodynamical instability.
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1988-04 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New trends in turbulence Turbulence nouveaux aspects written by M. Lesieur and published by Springer Science & Business Media. This book was released on 2003-07-01 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following a longstanding tradition of the Les Houches Summer Schools, this book uses a pedagogically presented and accessible style to treat 2D and 3D turbulence from the experimental, theoretical and computational points of view.
Download or read book The Global Geometry of Turbulence written by Javier Jiménez and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this Advanced Research Workshop was to bring together Physicists, Applied Mathematicians and Fluid Dynamicists, including very specially experimentalists, to review the available knowledge on the global structural aspects of turbulent flows, with an especial emphasis on open systems, and to try to reach a consensus on their possible relationship to recent advances in the understanding of the behaviour of low dimensional dynamical systems and amplitude equations. A lot has been learned during recent years on the non-equilibrium behaviour of low dimen sional dynamical systems, including some fluid flows (Rayleigh-Benard, Taylor-Couette, etc. ). These are mostly closed flows and many of the global structural features of the low dimensional systems have been observed in them, including chaotic behaviour, period doubling, intermit tency, etc. . It has also been shown that some of these flows are intrinsically low dimensional, which accounts for much of the observed similarities. Open flows seem to be different, and experimental observations point to an intrinsic high dimensionality. However, some of the tran sitional features of the low dimensional systems have been observed in them, specially in the intermittent behaviour of subcritical flows (pipes, channels, boundary layers with suction, etc. ), and in the large scale geometry of coherent structures of free shear flows (mixing layers, jets and wakes).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct and Large Eddy Simulation IV written by Bernard Geurts and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the proceedings of the 2001 DLES4 workshop. It describes and discusses state-of-the-art modeling and simulation approaches for complex flows. Fundamental turbulence and modeling issues but also elements from modern numerical analysis are at the heart of this field of interest.
