Download or read book Turbulent Wakes in a Stratified Medium written by T. R. Sundaram and published by . This book was released on 1971 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Wake in a Stratified Medium Trubulentnyy Sled V Stratifitsirovannoy Srede written by A. T. Onufriyev and published by . This book was released on 1977 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The article discusses the problem of determining the shape of a turbulent wake formed behind a self-propelled body in a medium with a density variable in the direction of action of gravity. A schematic picture of the development of the wake behind the moving object is as follows: at the outset, the diffusion is the same in all directions, and the wake expands symmetrically; with increasing distance from the object, the diffusion becomes strongly anisotropic, it decreases in the vertical direction under the action of gravity, and the wake assumes a flattened shape; in the volume occupied by the wake, turbulent mixing within the wake gives rise to a more homogeneous density distribution than in the ambient medium; this volume of liquid is no longer in a state of equilibrium and, acted upon by gravity, tends to return to this state; the wake collapses, and this is accompanied by its further expansion in the horizontal direction and excitation of internal waves.
Download or read book Experiments on Turbulent Wakes in a Stable Density stratified Environment written by Walter P. M. van de Watering and published by . This book was released on 1969 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a laboratory experiment, turbulent mixed regions were generated in a linearly density-stratified fluid and their behavior was studied. Such regions may occur in nature in the atmosphere and in the ocean. Particularly during their early history, the shape of such regions is influenced by the interacting effects of turbulence and buoyancy, culminating in the occurrence of a maximum thickness and subsequent vertical collapse. A Richardson number (equivalent to the ratio of the characteristic turbulence time and the Vaisala period) was found satisfactorily to correlate the data obtained, together with those previously obtained by other investigators with self-propelled bodies. An estimate is made of the degree of mixing that takes place inside a turbulent mixed region during its growth in stably-stratified surroundings: the effectiveness of this mixing determines the ultimate thickness to which the mixing region collapses. (Author).
Download or read book Collapse of Turbulent Wakes in Density stratified Media written by Jin Wu and published by . This book was released on 1965 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wake generated by a submerged body moving through a density-stratified medium consists not only of a region of turbulence but also of a region of water with homogeneous density. The purpose of the present research is to study phenomena and modeling criteria relating to the collapse of this wake. Since the wake is very slender in the direction of the body passage, this problem is simplified by studying only the collapse of a particular transverse section of the wake. An experimental technique was successfully developed by using a wall-mixer to model the collapsing phenomen of a two-dimensional wake in densitystratified media. The process of collapse can be divided into three stages: 'initial', 'principal' and 'final' collapse stages. Empirical formulae were derived to describe the collapse processes of the first two stages, during which the gravitational effect is found to be the predominant modeling criterion. The collapsing process in the final stage was complicated by the increasing viscous effect and observed mixing at the thin wake tip. (Author).
Download or read book A Phenomenological Model for the Momentumless Turbulent Wake in a Stratified Medium written by D. R. S. Ko and published by . This book was released on 1973 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth and collapse of the turbulent wake behind a submarine in a stratified ocean is studied analytically using simple phenomenological models. The present analysis closely follows a previous integral approach based on the concept of local similarity and turbulent entrainment. A nonuniform entrainment rate, obtained by considering the three turbulent velocity components separately, marks the main difference to the previous approach. The present analysis is limited to a wake without swirl and does not include the energy leakage through the internal wave field.
Download or read book Turbulent Wakes in a Stratified Fluid Part 1 Model Development Verification and Sensitivity to Initial Conditions written by W. S. Lewellen and published by . This book was released on 1974 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational model has been developed for the turbulent wake of a body moving through a stably stratified fluid. Details of the wake growth, collapse and generation of internal waves were examined by the application of a second-order closure approach to turbulent flow developed at A.R.A.P. over the past few years. Predictions of the model have been verified by comparison with a wide variety of wake flows including wakes with no momentum, wakes with axial momentum, wakes with angular momentum, and for wakes in both stratified and unstratified fluids. A sensitivity investigation reveals that the primary variable affecting the strength of the generated internal waves is the initial Richardson number, with the first local maximum of the vertical height of the wake scaling inversely with the 1/8th power of the initial Richardson number.
Download or read book Submarine Wake Modeling written by Robert L. Gran and published by . This book was released on 1973 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Collapse of Turbulent Wakes in Stably Stratified Media written by S. Hassid and published by . This book was released on 1977 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple turbulent energy model and a calculation procedure are proposed, which are able to reproduce the main features of the collapse of turbulent wakes behind towed or self propelled bodies in stratified environments. The predictions of the model are shown to be in good agreement with the detailed experimental data of Lin and Pao, as well as with the flow visualization experiments of other workers. (Author).
Download or read book The Growth of a Turbulent Wake in a Density stratified Fluid written by Walter P. M. van de Watering and published by . This book was released on 1966 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The force of gravity causes a turbulent wake in a density-stratified fluid to eventually cease its vertical growth and then to collapse towards its horizontal midplane. In the present investigation this phenomenon was studied experimentally. The turbulent wake was created by means of a spiral paddle, agitated by a pendulum-type arrangement outside a transparent lucite tank. Data were obtained from tracings of the motion pictures taken by a 16 mm movie camera. Both the pendulum arrangement and the paddle diameter were varied to find the possible influence of the experimental conditions. It was observed that the initial rate of growth in the vertical direction is constant, depending primarily on the density gradient and the agitation mechanism (i.e. pendulum and paddle diameter). This initial rate of growth of the wake, the maximum vertical thickness of the wake, the time at which collapse begins and the turbulence intensity within the wake at that time, were all correlated with the Vaisala frequency, resulting in three important constants which seemed to be independent of the experimental conditions. (Author).
Download or read book NBS Special Publication written by and published by . This book was released on 1974 with total page 784 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 Turbulent Wakes in a Stratified Flow written by Christos Christakis Alexopoulos and published by . This book was released on 1968 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution Simulation of the Turbulent Wake Behind a Sphere in a Stratified Fluid written by Matthew Bronson De Stadler and published by . This book was released on 2013 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wake of a bluff body is significantly modified by the presence of a stable density stratification. Buoyancy effects introduce a complex coupling between kinetic and potential energy which results in a significantly longer wake lifetime, internal wave radiation, and long lived coherent structures. This dissertation presents results obtained from high resolution numerical simulations of stratified turbulent wakes. The dissertation is divided into two parts. The first part of the dissertation uses the well established temporal approximation to simulate from the near wake to the far wake. In this part of the dissertation, the effect of the Prandtl number on a stratified turbulent wake was considered. For 0.2 Pr
Download or read book Closure Strategies for Turbulent and Transitional Flows written by Brian Edward Launder and published by Cambridge University Press. This book was released on 2002-02-21 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Download or read book Turbulent Wakes in Density Stratified Fluids of Finite Extent written by Edmund A. Prych and published by . This book was released on 1964 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented of an investigation of the effects of a free surface and density stratification of the turbulent transfer of mass and momentum in two-dimensional wakes. The effect of depth of submergence on the drag of a twodimensional body was also investigated.
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 Mathematical Models and Integration Methods written by Oleg V. Kaptsov and published by Walter de Gruyter GmbH & Co KG. This book was released on 2024-09-23 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book compiles works presented at a seminar aiming to attract global experts in differential equations, mathematical modeling, and integration methods. It covers classical and contemporary integration techniques for partial differential equations, including Monge and Darboux's approaches and their extensions. Additionally, it introduces a novel theoretical model for plane turbulent flows, presents gravitational equations derived from the principle of least action, and explores symmetry-preserving conservative finite-difference schemes for hydrodynamic-type equations. Analytical solutions for Maxwell's equations in incompressible viscoelastic mediums are examined, alongside theoretical-group analysis of wake mathematical models and reduction to ordinary differential equations. The book also delves into special classes of two-dimensional ideal fluid motion and advancements in discrete orthogonal polynomial theory, showcasing rapid decay properties near interval boundaries. In conclusion, this comprehensive collection is indispensable for researchers and practitioners in applied mathematics, fluid dynamics, and computational modeling, providing valuable insights into cutting-edge methods and solutions in the field.
