Download or read book Interaction of an Embedded Longitudinal Vortex with an Attached Three dimensional Turbulent Boundary Layer written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1990 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mean Flow Development of a Longitudinal Vortex Embedded in an Attached Three dimensional Turbulent Boundary Layer written by and published by . This book was released on 1990 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of a longitudinal vortex with a pressure-driven, three dimensional turbulent boundary layer was investigated experimentally. The vortex was attenuated much more rapidly in the three dimensional layer than in a two-dimensional boundary layer. The persistence for the vortex-induced perturbation was strongly dependent on the sign of the vortex.

Download or read book Three dimensional Turbulent Boundary Layers written by O. Sendstad and published by . This book was released on 1992 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbulence Measurements for a Longitudinal Vortex Interacting with a Three dimensional Turbulent Boundary Layer written by Takaaki Shizawa 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 Proceedings of the Ninth Symposium on Energy Engineering Sciences written by and published by . This book was released on 1991 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Interactions in High Speed Boundary Layer Flows written by George R. Inger and published by . This book was released on 1985 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is the basic theoretical investigation of three-dimensional pressure, skin friction, and heat transfer disturbances in both laminar and turbulent boundary layer flows including viscous-inviscid interaction effects, separation, and reattachment. A sound understanding of these phenomena is required in modern aerodynamic design analyses of high-speed flight vehicles. The primary emphasis in these studies has been to seek a basic physical understanding of the underlying fluid behavior by means of analytically-oriented methods; in this way, the results can be used to guide and interpret concurrent experimental and computationally-oriented investigations. This inquiry has focused on two parallel paths of investigation: three-dimensional, viscous-inviscid interaction phenomena within turbulent boundary layers in supersonic flow due to impinging swept shock and/or 3-D surface deflections, and streamwise vortex-disturbance mechanisms within laminar or turbulent boundary layers that are either separated or attached.

Download or read book The Interaction Between a Non embedded Longitudinal Vortex and Turbulent Boundary Layer Under the Influence of Streamwise Pressure Gradient written by Joseph Creazzo and published by . This book was released on 1999 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three Dimensional Vortex Interactions in Turbulent Boundary Layers written by C. R. Smith and published by . This book was released on 1985 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combined analytical experimental program, which has as its continuing objective the detailed investigation of the three dimensional vortex interactions which take place in turbulent boundary layers, is described and the accomplishments detailed. The analytical and numerical studies have examined both the development and characteristics of loop and hairpin vortices in both uniform and shear flows; particular attention has been paid to the strong three dimensional, inviscid viscous interaction of these types of vortical flow structures with wall region fluid. The experimental studies have focussed on the creation & detailed examination of three dimensional hairpin vortices, developing flow visualization patterns for cross-comparison with both the analytical studies and fully turbulent boundary layer flows. A technique for developing quantitative data by image processing of the visualization patterns is also described. Keywords: Turbulent boundary layer; Coherent structure; Flow visualization; Numerical modelling; Vortex wall interactions; Computer aided analysis; Loop vortices; Hairpin vortices.

Download or read book Three dimensional Vortex body Interaction in a Viscous Fluid written by Jeffrey S. Marshall and published by . This book was released on 1999 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and computational study of the impact of a vortex with a body oriented normal to the vortex axis was performed. Particular focus was placed on understanding characteristics of the secondary vorticity ejected from the body and the interaction of the secondary vorticity with the primary vortex. Since both onset of boundary layer separation and the form of the secondary vorticity structures are sensitive to variation of the velocity normal to the body axis, the effect of normal velocity on vortex-body interaction was carefully examined. The physical features of the flow evolution were categorized in terms of an impact parameter and a thickness parameter, which respectively represent ratios of velocity and length scales associated with the vortex to those associated with the flow in the absence of the vortex. Experiments were performed using a combination of laser-induced fluorescence (LIF) flow visualization and particle-image velocimetry (PIV) in a water tank to examine the form of the secondary vorticity structures with both "high" and "low" values of the impact parameter for normal vortex interaction with a circular cylinder and with a thin blade. A new type of Lagrangian vorticity method based on a tetrahedral mesh was developed and applied to compute the secondary vorticity evolution during vortex-cylinder interaction. Computations were also performed for model problems to examine in detail wrapping of a vortex loop around a columnar vortex and impulsive cutting of a columnar vortex with finite axial flow.

Download or read book On Nonlinear Tollmien Schlichting vortex Interaction in Three Dimensional Boundary Layers written by Dominic A. R. Davis and published by . This book was released on 1993 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Nonlinear Tollmien Schlichting Vortex Interaction in Three Dimensional Boundary Layers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The instability of an incompressible three-dimensional boundary layer (that is, one with cross-flow) is considered theoretically and computationally in the context of vortex/wave interactions. Specifically the work centers on two low amplitude, lower-branch Tollmien-Schlichting waves which mutually interact to induce a weak longitudinal vortex flow; the vortex motion, in turn, gives rise to significant wave-modulation via wall-shear forcing. The characteristic Reynolds number is taken as a large parameter and, as a consequence, the waves' and the vortex motion are governed primarily by triple-deck theory. The nonlinear interaction is captured by a viscous partial-differential system for the vortex coupled with a pair of amplitude equations for each wave pressure. Three distinct possibilities were found to emerge for the nonlinear behavior of the flow solution downstream - an algebraic finite-distance singularity, far downstream saturation or far-downstream wave-decay (leaving pure vortex flow) - depending on the input conditions, the wave angles, and the size of the cross-flow. Davis, Dominic A. R. and Smith, Frank T. Glenn Research Center NCC3-233; RTOP 505-62-21...

Download or read book Legislazione e controllo igienico del latte in Svizzera written by and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Near Wall Investigation of Three Dimensional Turbulent Boundary Layers written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents the experimental study for four different three-dimensional turbulent flows. The investigation focuses on near wall measurements in these flows. Several experimental techniques are used in the studies; however, the bulk of the investigation focuses on a three-orthogonal-velocity-component fiber-optic laser Doppler anemometer (3D-LDA) system. The control volume of the 3D-LDA is on the order of 50 micrometer in size, or a y(+) distance of around 2.3 units. An auxiliary small boundary layer wind tunnel (auxiliary tunnel) and a low speed linear compressor cascade wind tunnel (cascade tunnel) are utilized in this study. One of four flow experiments is done in the auxiliary tunnel the other three are in the cascade tunnel. The first three-dimensional turbulent flow is a vortical flow created by two half-delta wing vortex generators. Near wall secondary flow features are found. The second flow is an investigation of the first quarter chord tip gap flow in the cascade tunnel. Strong three-dimensional phenomena are found. The third flow investigated is the inflow to the compressor cascade with the moving wall. The experiment records shear layer interaction between the upstream flow and moving wall. Finally the fourth flow investigated is the inflow to the compressor cascade with the moving wall with half-delta wing vortex generators attached. Phase-averaged data reveal asymmetrical vortex structures just downstream of the vortex generators. This is the first time near wall turbulence data have been taken on these types of flows.

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Interaction of Wake boundary layer and Vortex boundary layer written by C. P. Yeung and published by . This book was released on 1993 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbulence Structure Resulting from Interaction Between an Embedded Vortex and Wall Jet written by James G. Green and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interactions of wall jets and vortices embedded in turbulent boundary layers commonly occur near gas turbine blades and endwalls where film cooling is employed. These interactions frequently result in undesirable heat transfer effects at blade and endwall surfaces. In this research, a crossed hot-wire probe is used to measure the turbulence structure resulting from this type of interaction. The vortex is generated using a half-delta-wing vortex generator mounted at 12 degrees with respect to a 10 m/s mean velocity flow over a flat plate. A single injection hole, .95 cm in diameter, inclined 30 degrees to the horizontal, is located under the vortex downwash, 58 cm downstream from the vortex generator. Baseline measurements were made at one streamwise location downstream of the injection hole for the cases: (1) boundary layer only; (2) boundary layer with vortex, and (3) boundary layer with wall jet. Measurement of the interaction between the boundary layer, vortex and 2.5 blowing ratio wall jet was also made at this location. The 1.5 blowing ratio wall jet interaction was measured at three additional streamwise locations. Reynolds stress tensor components, vorticity distributions and mean velocities show that the vortex significantly alters the turbulence structure of the 1.5 blowing ratio wall jet at all four streamwise locations. Here the injectant is swept away from the injection hole by the vortex rotation. The most significant alterations to the turbulence structure occur in the vortex upwash region and beneath the vortex core. The 2.5 blowing ratio jet is much more resistant to disturbance by the vortex. (kr).