Download or read book Numerical Simulation of Collapsing Turbulent Wakes written by Alex. C. Warn-Varnas and published by . This book was released on 1979 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collapse of a partially mixed region generated by a prescribed amount of turbulence deposited on a linearly stratified ambient ocean is studied numerically. Different turbulent closures such as first and second order are used to model the turbulent stresses. The resulting equations are solved numerically in a finite-difference formalism of the primitive form of the equations in a box region several times the size of the mixed region. The resulting maximum observed mean field velocities, densities, and turbulent energies in the fluid are obtained and cross-compared for different closures and numerical methods.
Download or read book Numerical Simulation of Collapsing Turbulent Wakes written by and published by . This book was released on 1979 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collapse of a partially mixed region generated by a prescribed amount of turbulence deposited on a linearly stratified ambient ocean is studied numerically. Different turbulent closures such as first and second order are used to model the turbulent stresses. The resulting equations are solved numerically in a finite-difference formalism of the primitive form of the equations in a box region several times the size of the mixed region. The resulting maximum observed mean field velocities, densities, and turbulent energies in the fluid are obtained and cross-compared for different closures and numerical methods.
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 Direct numerical simulation of weakly stratified turbulent wake written by T. S. Lund and published by . This book was released on 2014 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report of NRL Progress written by Naval Research Laboratory (U.S.) and published by . This book was released on 1979 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of a Planar Turbulent Wake in Arbitrary Pressure Gradient written by Gregory P. Brooks and published by . This book was released on 1999 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex wakes of Aircrafts written by A.S. Ginevsky and published by Springer Science & Business Media. This book was released on 2009-07-07 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing’s trailing edge are long lived and attenuate only atdistances of10–12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft’s encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport’s ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft’s movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier–Stokes equations, large eddy simulation using the Navier–Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries’ scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.
Download or read book Direct Simulation of a Self similar Plane Wake written by Robert D. Moser and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Some Comments on the Modeling of the Turbulent Wake of a Self Propelled Body in a Stratified Fluid written by Edward Y. T. Kuo and published by . This book was released on 1972 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modeling of the turbulent wake of a self-propelled body in a stratified fluid is discussed. The scaling parameter is taken to be the internal Froude number, using the speed and diameter of the body and Vaisala frequency of the fluid. The ratio of the time for the wake to collapse to the characteristic time of the turbulence is related to model scale when the wake is turbulent up to and including the collapse. A number of criteria for turbulent wake are discussed. Numerical estimates are made, assuming typical values of the model speed and of the Vaisala frequency, of the minimum model size necessary for the existence of a turbulent wake at collapse.
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 Modeling Simulation and Optimization of Complex Processes written by Hans Georg Bock and published by Springer Science & Business Media. This book was released on 2008-06-19 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume covers the broad interdisciplinary spectrum of scientific computing and presents recent advances in theory, development of methods, and applications in practice.
Download or read book Twenty Second Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2000-03-02 with total page 1039 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.
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 Numerical Simulation of a Plane Wake written by Socrates G. Potamitis and published by . This book was released on 1992 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:
