Download or read book Dynamics of Stratified Flow Past a Sphere written by Anikesh Pal and published by . This book was released on 2016 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wakes of bluff bodies in a stratified environment are common in oceanic and atmospheric flows. Some examples are marine swimmers, underwater submersibles and flow over mountains and islands. The first part of the research in stratified wakes concerns temporal/spatial simulations of turbulent self-propelled/towed wakes without including a body. Direct numerical simulations are performed to contrast the influence of the mean velocity profile with that of the initial turbulence on the subsequent evolution of velocity and density fluctuations in a stratified self-propelled wake. It is also verified that results of temporal simulations matches with that of the spatial simulations when the initial near-wake condition of the temporal approximation is chosen to match the inflow of the spatially evolving model. Typically, the wake of a body develops in the presence of external fluctuations, motivating a study of wake evolution under the influence of various intensities of external turbulence. The stratified wake was found to decay substantially faster than its unstratified counterpart for same intensity of the external turbulence. Theoretical arguments and additional simulations were performed to show that the level of external turbulence relative to wake turbulence is a key governing parameter in both stratified and unstratified backgrounds. The second part of this research focuses on flow past a sphere in a stratified fluid at a sub-critical Reynolds number of 3,700 and for a range of Froude numbers U/ND \in [0.025,1]. The conservation equations are solved in a cylindrical coordinate system and an immersed boundary method is employed to represent the sphere. The prime objective of this investigation is to understand the statistical response of the near, intermediate and far wake of a sphere at sub-critical Re under the influence of buoyancy. It is observed that buoyancy leads to the inhibition of vertical motion resulting in faster decay of r.m.s. velocity in the vertical direction as compared to the horizontal r.m.s. velocity, collapse of the wake, propagation of internal gravity waves and the organization of the primarily horizontal flow into coherent vortical structures. Unprecedented with respect to previous studies, the time averaged turbulent kinetic energy budget is closed for the unstratified and stratified cases. A novel finding of this research is the regeneration of turbulent fluctuations in the near wake when the stratification increases beyond a critical level (Fr decreases beyond a critical value) which is in contrast to the previous results at lower Re that suggest monotone suppression of turbulence with increasing stratification. Vorticity evolution, energy spectra and the turbulence energy equation explain turbulence regeneration. Another objective of this study is to quantify the distinction between the body and turbulence generated internal waves, in terms of the amplitude, frequency, potential energy distribution and propagation angles. With a decrease in Fr, the body generation mechanism become stronger and waves exhibit upstream propagation.
Download or read book Linearly Stratified Flow Past a Sphere written by Qiang Lin and published by . This book was released on 1993 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stratified Flows written by Chia-Shun Yih and published by Elsevier. This book was released on 2012-12-02 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stratified Flows is the second edition of the book Dynamics of Nonhomogenous Fluids. This book discusses the flow of a fluid of variable density or entropy in a gravitational field. In this edition, corrections have been made; unnecessary parts have been omitted; and new sections as well as notes on results related to the subject have been added. This book includes a general discussion of the effects of density or entropy and the structure of stratified flows; waves of small amplitude; the Eigenvalue problem; dependence of phase velocity on wavelength; wave motion; steady flows of finite amplitude; and types of solutions for steady flows. This edition also covers other topics such as hydrodynamic stability; flows in porous media; and the analogy between gravitational and electromagnetic forces. This text is recommended for those in the field of physics who would like to be familiarized with stratified flows and its related concepts.
Download or read book Flow about a Sphere in a Stratified Fluid Column written by Thomas A. Kiriyanthan and published by . This book was released on 1990 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Parallel Computational Fluid Dynamics 2007 written by Ismail H. Tuncer and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the 19th Annual Conference on Parallel Computational Fluid Dynamics held in Antalya, Turkey, in May 2007, the most recent developments and implementations of large-scale and grid computing were presented. This book, comprised of the invited and selected papers of this conference, details those advances, which are of particular interest to CFD and CFD-related communities. It also offers the results related to applications of various scientific and engineering problems involving flows and flow-related topics. Intended for CFD researchers and graduate students, this book is a state-of-the-art presentation of the relevant methodology and implementation techniques of large-scale computing.
Download or read book Incompressible Fluid Dynamics written by P. A. Davidson and published by Oxford University Press. This book was released on 2022 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: Incompressible Fluid Dynamics is a textbook for graduate and advanced undergraduate students of engineering, applied mathematics, and geophysics. The text comprises topics that establish the broad conceptual framework of the subject, expose key phenomena, and play an important role in the myriad of applications that exist in both nature and technology. The first half of the book covers topics that include the inviscid equations of Euler and Bernoulli, the Navier-Stokes equation and some of its simpler exact solutions, laminar boundary layers and jets, potential flow theory with its various applications to aerodynamics, the theory of surface gravity waves, and flows with negligible inertia, such as suspensions, lubrication layers, and swimming micro-organisms. The second half is more specialised. Vortex dynamics, which is so essential to many natural phenomena in fluid mechanics, is developed in detail. This is followed by chapters on stratified fluids and flows subject to a strong background rotation, both topics being central to our understanding of atmospheric and oceanic flows. Fluid instabilities and the transition to turbulence are also covered, followed by two chapters on fully developed turbulence. The text is largely self-contained, and aims to combine mathematical precision with a breadth of engineering and geophysical applications. Throughout, physical insight is given priority over mathematical detail.
Download or read book Parallel Computational Fluid Dynamics 2003 written by Boris Chetverushkin and published by Elsevier. This book was released on 2004-05-06 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is devoted to using of parallel multiprocessor computer systems for numerical simulation of the problems which can be described by the equations of continuum mechanics. Parallel algorithms and software, the problems of meta-computing are discussed in details, some results of high performance simulation of modern gas dynamic problems, combustion phenomena, plasma physics etc are presented.·Parallel Algorithms for Multidisciplinary Studies
Download or read book Environmental Stratified Flows written by Roger Grimshaw and published by Springer Science & Business Media. This book was released on 2006-04-11 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dynamics of flows in density-stratified fluids has been and remains now an important topic for scientific enquiry. Such flows arise in many contexts, ranging from industrial settings to the oceanic and atmospheric environments. It is the latter topic which is the focus of this book. Both the ocean and atmosphere are characterised by the basic vertical density stratification, and this feature can affect the dynamics on all scales ranging from the micro-scale to the planetary scale. The aim of this book is to provide a “state-of-the-art” account of stratified flows as they are relevant to the ocean and atmosphere with a primary focus on meso-scale phenomena; that is, on phenomena whose time and space scales are such that the density stratification is a dominant effect, so that frictional and diffusive effects on the one hand and the effects of the earth’s rotation on the other hand can be regarded as of less importance. This in turn leads to an emphasis on internal waves.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1974 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Marine Propulsors written by Sverre Steen and published by MDPI. This book was released on 2018-10-10 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Marine Propulsors" that was published in JMSE
Download or read book Experimental Investigation of Turbulent Flows Around a Sphere written by Vukman Bakić and published by . This book was released on 2003 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Twenty First Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 1997-09-11 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Internal Structure and Dynamics of Stratified Flow Over Sloping Topography written by Lars Umlauf and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluid Mechanics written by Pijush K. Kundu and published by Elsevier. This book was released on 2013-04-09 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written in a clear and simple style, this textbook on fluid mechanics gives equal emphasis to both geophysical and engineering fluid mechanics. For physicists, it contains chapters on geophysical fluid mechanics and gravity waves; for engineers, it has chapters on aerodynamics and compressible flow. Of common interest are chapters on governing equations, laminar flows, boundary layers, instability, and turbulence. This book also presents topics of recent interest, such as deterministic chaos, and double-diffusive instability.n Gives equal treatment to topics in both engineering and geophysical fluid dynamicsn Suitable as an intermediate or graduate course textbook for students in their senior year or aboven Treats topics of recent interest such as deterministic chaos, double diffusive instability and solitonn Extensively illustratedn Contains fully worked examples in each chapter as well as end-of-chapter problemsn An instructor's manual is available
Download or read book Waves and Turbulence in Stably Stratified Flows written by S. D. Mobbs and published by Oxford University Press, USA. This book was released on 1993 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume, containing twenty papers, includes the majority of those presented at the third IMA conference on stably stratified flows, held in Leeds in December 1989. The theme of the conference was waves and turbulence in stably stratified flows, although papers covering other aspects ofstably stratified flows are also included. A wide variety of techniques are described, ranging from numerical simulation, through laboratory studies, to field observations of the atmosphere. Some papers address fundamental aspects of turbulence in stably stratfied flows such as turbulence collapseand local scaling. Six of the papers report investigations motivated by Antarctic field studies, reflecting the importance of that region for research on the stably stratified atmosphere. Eight papers deal with aspects of mixing in stably stratified flows, of which four are directly concerned withindustrial applications. Observations of atmospheric internal gravity waves are discussed in two papers whilst a further two report studies of rotating, stratified flows with application to large-scale atmospheric and oceanic dynamics.
Download or read book A Ship Advancing in a Stratified Fluid written by Mehdi Esmaeilpour and published by . This book was released on 2017 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational fluid dynamics (CFD) methodology is presented to predict density stratified flows in the near-field of ships and submarines. The density is solved using a higher-order transport equation coupled with mass and momentum conservation. Turbulence is implemented with a k-ε/k-ω based Delayed Detached Eddy Simulation (DDES) approach, enabling explicit solution of larger energy-containing vortices in the wake. Validation tests are performed for a two-dimensional square cavity and the three-dimensional stratified flow past a sphere, showing good agreement with available data. The near-field flow of the self-propelled Research Vessel Athena advancing in a stably stratified fluid is studied, as well as the operation in stratified flow of the notional submarine Joubert BB2 also in self-propelled condition. The resulting density, velocity, pressure and turbulent quantities at the exit plane of the near-field computation contain a description of the relevant scales of the flow and can be used to compute the far-field stratified flow, including internal waves. The generation of internal waves is shown in the case of the submarine for two different conditions, one with the pycnocline located at the propeller centerline, and the second with the pycnocline located slightly below the submarine, concluding that distance to the pycnocline strongly affects the internal wave generation due to the presence of the vessel. It is also shown that, as in the case of surface waves, the generation of internal waves requires energy that results in an increase in resistance. For the case of the surface ship the near field wakes are mostly affected by the separation at the wet transom and propeller mixing. However, in the case of the underwater vessel, the disturbance of the background density profile by the presence of the submarine affects the near-field wakes.
Download or read book Observing the Oceans in Real Time written by R. Venkatesan and published by Springer. This book was released on 2017-11-17 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides contributions from leading experts on the integration of novel sensing technologies to yield unprecedented observations of coupled biological, chemical, and physical processes in the ocean from the macro to micro scale. Authoritative entries from experts around the globe provide first-hand information for oceanographers and researchers looking for solutions to measurement problems. Ocean observational techniques have seen rapid advances in the last few years and this book addresses the need for a single overview of present and future trends in near real time and real time. First the past, present and future scenarios of ocean observational tools and techniques are elucidated. Then this book divides into three modes of ocean observations: surface, upper ocean and deep ocean. This is followed by data quality and modelling. Collecting a summary of methods and applications, this book provides first-hand information for oceanographers and researchers looking for solutions to measurement problems. This book is also suitable for final year undergraduate students or beginning graduate students in ocean engineering, oceanography and various other engineering students (such as Mechanical, Civil, Electrical, and Bioengineering) who are interested in specializing their skills towards modern measurements of the ocean.
