Download or read book Three dimensional Turbulent Wake written by Yung-Huang Kuo and published by . This book was released on 1965 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Calculation of Three Dimensional Turbulent Wake boundary Layer Mixing Flows written by M. Nasrullah and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Control of Three dimensional Turbulent Wakes written by Mathieu Grandemange and published by . This book was released on 2013 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of the turbulent wake past different geometries is performed by increasing the complexity from axisymmetric bodies to road vehicles. Whatever the geometry is, two kinds of coherent wake motions are likely to be observed. First, at timescales of the order of 5D/U, D and U being the characteristic size and velocity of the flow respectively, the wake may generate periodic oscillations. These coherent motions are usually associated with the interaction of two facing shear layers of opposite vorticity. As the corresponding frequencies rely at first order on the distance between the shear layers, two distinct frequencies are reported when the afterbody has a cross-flow aspect ratio different than 1. These unsteady global modes seem to weaken when the Reynolds number and the complexity of the geometry increase. The second type of coherent motions corresponds to the development of stationary cross-flow instabilities. They are linked to the symmetry breaking modes observed in laminar regimes and their domains of appearance are defined from geometry considerations in the cases of parallelepiped bodies in ground proximity. These instabilities are responsible for strong asymmetries in the instantaneous flow and may generate bistable dynamics with a characteristic time scale of the order of 1000D/U. The study of these phenomena, combined with sensitivity analyses to small perturbations, places the diminution of the cross-flow asymmetries of the instantaneous wake as a relevant strategy for drag reduction. In particular, it is found that both local and global pressure gradients on the sides of the body are source of streamwise vortices increasing the drag. Parabolic dependences between the drag and the cross-flow forces are reported suggesting similarities with the mechanisms of induced drag that are well-known in aeronautics. Consequently, as they often generate significant wake asymmetries, the development of the cross-flow instabilities is identified as a drag contributor. On the contrary, the part of the drag related to the periodic global modes seems to be negligible especially for complex geometries at high Reynolds number.

Download or read book Analysis of Three dimensional Turbulent Wakes by Momentum Integral Technique written by B. Lakshminarayana and published by . This book was released on 1987 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particle Image Velocimetry written by Ronald J. Adrian and published by Cambridge University Press. This book was released on 2011 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle image velocimetry, or PIV, refers to a class of methods used in experimental fluid mechanics to determine instantaneous fields of the vector velocity by measuring the displacements of numerous fine particles that accurately follow the motion of the fluid. Although the concept of measuring particle displacements is simple in essence, the factors that need to be addressed to design and implement PIV systems that achieve reliable, accurate, and fast measurements and to interpret the results are surprisingly numerous. The aim of this book is to analyze and explain them comprehensively.

Download or read book Three dimensional Structure in Laminar and Turbulent Wakes written by Anil Prasad and published by . This book was released on 1996 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase averaged Large scale Structures in Three dimensional Turbulent Wakes written by Jonathon Hugh Watmuff and published by . This book was released on 1979 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ASME 65 WA FE 1 written by F. J. Pierce and published by . This book was released on 1965 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of a Three dimensional Wake written by G. Pailhas and published by . This book was released on 1989 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Momentumless Wakes in Density stratified Liquids written by Philip Joseph Stockhausen and published by . This book was released on 1966 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were performed to investigate the configuration and surface effects of the turbulent wake generated by a self-propelled body moving in a linearly density-stratified liquid. The experiments were performed in a 50-foot long tank filled to a depth of 2 1/2 ft. For all experiments, the Reynolds number, based on the diameter of the circular disc mounted on the model's bow, was 89,000. It was found that the mixed region generated by the turbulent wak5 rapidly attained a maximum vertical extent, and then collapsed vertically while continuing to expand laterally. The vertical collapse of the wake was accompanied by the convergence toward the model of the fluid at the free surface. The convergence did not occur with homogeneous liquids. It was concluded that this surface convergence is possible only if the turbulent wake extends to the free surface. A new method was developed for generating linear density profiles in large tanks. (Author).

Download or read book Turbulent Structures in a Supersonic Three dimensional Blunt body Wake written by Alan L. Kastengren and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial Instability of Compressible Wakes with Three dimensional Disturbances written by Y. Y. Chan and published by 1974.. This book was released on 1974 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The linear spatial stability of a compressible thin turbulent wake bound by two side walls is analyzed by the stability theory of an inviscid shear flow. The disturbance propagating in the wake is assumed to be three-dimensional. For free stream Mach numbers up to 2 the analysis shows that in the high frequency region the most unstable mode of the wake is induced by two-dimensional disturbances. However, at the low frequency region the wake is more unstable to three-dimensional disturbances than to two-dimensional ones.

Download or read book Three Dimensional Turbulent Shear Flows written by S. Carmi and published by . This book was released on 1982 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toward Three dimensional Modeling of a Wake Vortex Pair in the Turbulent Planetary Boundary Layer written by D. G. Schowalter and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Streamline Iteration Method for Computing the Three dimensional Turbulent Flow Around the Stern and in the Wake of Ship written by Shan Huang and published by . This book was released on 1986 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Interactions and Vortical Flows with Emphasis on High Speeds written by David J. Peake and published by . This book was released on 1980 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Three dimensional Wake Behind an Obstacle on a Flat Plate written by Robert F. Mons and published by . This book was released on 1968 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of the three-dimensional, incompressible wake behind a blunt obstacle located at the leading edge of a flat plate is presented. Configurations studied included the 'clean' flat plate, and the flat plate with a rectangular, a square, or a two-dimensional obstacle fitted to the leading edge of the plate. Experimental results are compared to a mathematical model based on the Oseen linearization for diffusive flows. Based on mean flow measurements, a transition to turbulent flow was not encountered for any of the configurations examined. Such wakes are characterized by a region of strong vorticity immediately behind the obstacle followed by a region of viscous dissusion. Bulk properties of the wake-like flow and the applicability of the theoretical model were found to be highly dependent on the geometry of the obstacle. (Author).