Download or read book Numerical Simulation of Vortex Breakdown Via 3 D Euler Equations written by T. H. Lê and published by . This book was released on 1989 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three dimensional Simulation of Vortex Breakdown written by and published by . This book was released on 1990 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Three dimensional Vortex Breakdown written by Robert Edward Spall and published by . This book was released on 1987 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Vortex Breakdown by the Vortex filament Method written by Y. Nakamura and published by . This book was released on 1983 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vortex-filament method was applied to the simulation of vortex breakdown. The principal vortex region was represented by multiple filaments, and an axial velocity component was induced by a spiral winding of the filaments. First, an accuracy check was performed for a cylindrical swirling flow field that can be simulated to any accuracy by increasing the number of filaments. Second, an axisymmetric-type vortex breakdown was simulated, with experimental data serving asupstream conditions. The calculated axial- and theta-velocity contours show the breakdown of the vortex, including a rapid change in the vortex core, followed axially by a recovery zone and then a second breakdown. When three-dimensional initial data are used the second breakdown appears to be out of the spiral type in correspondence with experimental observations. The present method can easily be used to simulate other types of vortex breakdown or other vortex flows with axial velocity.
Download or read book Numerical Simulation of Vortex Breakdown written by Jasim Uddin Ahmad and published by . This book was released on 1989 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three Dimensional Simulation of Vortex Breakdown written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state. Kuruvila, G. and Salas, M. D. Langley Research Center...
Download or read book Vortex Methods written by Georges-Henri Cottet and published by Cambridge University Press. This book was released on 2008-04-24 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vortex methods have matured in recent years, offering an interesting alternative to finite difference and spectral methods for high resolution numerical solutions of the Navier Stokes equations. In the past three decades, research into the numerical analysis aspects of vortex methods has provided a solid mathematical background for understanding the accuracy and stability of the method. At the same time vortex methods retain their appealing physical character, which was the motivation for their introduction. This book presents and analyzes vortex methods as a tool for the direct numerical simulation of impressible viscous flows. It will interest graduate students and researchers in numerical analysis and fluid mechanics and also serve as an ideal textbook for courses in fluid dynamics.
Download or read book Numerical Simulation of Leading edge Vortex Rollup and Bursting written by Steven Allan Brandt and published by . This book was released on 1988 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vortex aerodynamics has played an important role in the development of high performance aircraft in recent years. Although computer codes which solve the three dimensional Euler equations have been used extensively to study leading-edge vortices, they don't include physical viscosity effects associated with vortex flows. The Euler solvers do, however, contain numerical viscosity. As a result, viscosity effects in the Euler solutions such as vortex core size, vortex burst location, leading edge separation, and vortex rollup often do not agree quantitatively with results of physical experiments. The present work defines models for these physical viscosity effects which can be coupled with an Euler solver to improve modeling of vortex physics. A vortex core model is derived from the steady, incompressible Navier-Stokes equations written in cylindrical coordinates. The core model is coupled with an Euler solver and tested on a variety of delta wings over a range of angles of attack. The resulting surface pressure distributions and vortex burst locations are shown to be much closer than results from Euler codes alone. Theses. (jhd).
Download or read book Numerical Simulation of Unsteady Axisymmetric Vortex Breakdown Including Heat Transfer written by Elsayed Abdelfattah Shabana and published by . This book was released on 1994 with total page 240 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 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Three Dimensional Simulation of Vortex Breakdown written by Thomas John and published by . This book was released on 2001 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering A Cumulative Index to a Continuing Bibliography supplement 287 written by and published by . This book was released on 1993 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Vortex Breakdown written by and published by . This book was released on 1978 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vortex breakdown is simulated by a three dimensional Lagrangian method using vortex filaments. The filaments are approximated by vortex elements and their velocity is computed by a Biot-Savart type law of interaction. The numerical calculations show the development of an axisymmetric bubble with a recirculation zone and resemble in many respects the results obtained in the physical experiments on vortex breakdown.
Download or read book Direct Numerical Simulations of Highly Vortical Flows and Vortex Breakdown written by Wing Tsin Ma and published by . This book was released on 1995 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Symposium Transsonicum III written by Jürgen Zierep and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuing the tradition of the IUTAM Symposia TRANSSONICA, this review of the numerical simulation and physical modelling of transonic flows presents new developments in the fields of computational and experimental aerodynamics. A major topic of the symposium proceedings is the evaluation of present numerical analysis techniques with respect to transonic aerodynamics. In the field of experimental aerodynamics, the high Reynolds number effect and the interference-free testing in transonic wind tunnels are of special interest.
Download or read book Numerical Simulation of Transient Vortex Breakdown Above a Pitching Delta Wing written by and published by . This book was released on 1994 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational results are presented for transient vortex breakdown above a delta wing subject to a pitch-and-hold maneuver to high angle of attack. The flows are simulated by solving the full three-dimensional Navier-Stokes equations on a moving grid using the implicit Beam-Warming algorithm. An assessment of the effects of numerical resolution, and favorable comparison with experimental data suggest the computational approach captures the basic dynamics of this transient breakdown. The pressure gradient along the vortex axis is found to play a dominant role in the initiation of breakdown. A description of the three-dimensional instantaneous structure of the flow field is provided for the first time using critical-point theory. The reversed-flow region in the vortex core is associated with pairs of opposite spiral/saddle critical points. At its onset, the vortex breakdown is fairly axisymmetric; however, as it proceeds upstream and a stronger transition takes place along the axis, asymmetric effects become important and result in the formation of a bubble-type breakdown. This bubble structure is open and contains within itself a pair of stagnation points which are diametrically opposed and which rotate in the same sense as the base flow. Vortex breakdown, Delta wings, Unsteady aerodynamics, Computational fluid dynamics.
Download or read book Turbulence and Coherent Structures written by O. Métais and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last 25 years, one of the most striking advances in Fluid Mecha nics was certainly the discovery of coherent structures in turbulence: lab oratory experiments and numerical simulations have shown that most turbulent flows exhibit both spatially-organized large-scale structures and disorganized motions, generally at smaller scales. The develop ment of new measurement and visualization techniques have allowed a more precise characterization and investigation of these structures in the laboratory. Thanks to the unprecedented increase of computer power and to the development of efficient interactive three-dimensional colour graphics, computational fluid dynamicists can explore the still myste rious world of turbulence. However, many problems remain unsolved concerning the origin of these structures, their dynamics, and their in teraction with the disorganized motions. In this book will be found the latest results of experimentalists, theoreticians and numerical modellers interested in these topics. These coherent structures may appear on airplane wings or slender bodies, mixing layers, jets, wakes or boundary-layers. In free-shear flows and in boundary layers, the results presented here highlight the intense three-dimensional character of the vortices. The two-dimensional large scale eddies are very sensitive to three-dimensional perturbations, whose amplification leads to the formation of three-dimensional coherent vorti cal structures, such as streamwise, hairpin or horseshoe vortex filaments. This book focuses on modern aspects of turbulence study. Relations between turbulence theory and optimal control theory in mathematics are discussed. This may have important applications with regard to, e. g. , numerical weather forecasting.
