Download or read book Numerical Investigation of Two Streamwise Turbulent Jets in a Crossflow written by Tedi G. Ohanian and published by . This book was released on 2002 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical and Experimental Investigations of Two Side by side Round Turbulent Jets in a Cross Flow written by Carlos Alberto Orrala Poveda and published by . This book was released on 2004 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Numerical Study of Confined Turbulent Jets written by J. Zhu and published by . This book was released on 1993 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical investigation is reported of turbulent incompressible jets confined in two ducts, one cylindrical and the other conical with a 5 degree divergence. In each case, three Craya-Curtet numbers are considered which correspond, respectively, to flow situations with no moderate and strong recirculation. Turbulence closure is achieved by using the k-epsilon model and a recently proposed realizable Reynolds stress algebraic equation model that relates the Reynolds stresses explicitly to the quadratic terms of the mean velocity gradients and ensures the positiveness of each component of the turbulent kinetic energy. Calculations are carried out with a finite-volume procedure using boundary-fitted curvilinear coordinates. A second-order accurate, bounded convection scheme and sufficiently fine grids are used to prevent the solutions from being contaminated by numerical diffusion. The calculated results are compared extensively with the available experimental data. It is shown that the numerical methods presented are capable of capturing the essential flow features observed in the experiments and that the realizable Reynolds stress algebraic equation model performs much better than the k-epsilon model for this class of flows of great practical importance.

Download or read book An Experimental and Numerical Investigation of a Turbulent Round Jet Issuing Into an Unsteady Crossflow written by 夏麗萍 and published by Open Dissertation Press. This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "An Experimental and Numerical Investigation of a Turbulent Round Jet Issuing Into an Unsteady Crossflow" by 夏麗萍, Liping, Xia, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3123789 Subjects: Unsteady flow (Aerodynamics) Jets - Fluid dynamics

Download or read book Numerical Investigations of Multi Turbulent Jets in a Crossflow written by T. Ohanian and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experimental and Numerical Investigation of a Turbulent Round Jet Issuing Into an Unsteady Crossflow written by Liping Xia and published by . This book was released on 1998 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Turbulent Jet Impingement in a Confined Crossflow written by George D. Catalano and published by . This book was released on 1991 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements and computations are reported for the flow of a turbulent jet discharging into a crossflow confined between two parallel plates. For jet-to-crossflow velocity ratios R equal to 2 and 4, mean and fluctuating velocity components are measured by a laser Doppler anemometer. High order statistics of the streamwise velocity and its time derivative have been measured in the plane of symmetry of a jet in a confined crossflow. The existence of universal similarity of the fine scale structure of a developing turbulent velocity field and the validity of original Kolmogorov local similarity theory and later formulations were investigated. Construction of normalized spectral for energy content, dissipation, and higher order moments enable an examination of the Reynolds number dissipation, and higher order moments enable an examination of the Reynolds number dependence of these functions for the Re sub lamda range from 16 to 800. Estimates of the Kolmogorov constant, mu, ranging from 0.27 to 0.43 were obtained with the arithmetic average equal to 0.38. The fractal dimension of the fine scale structure was estimated from the functional relationship between the flatness of the velocity time derivative and Re sub lambda. For unfiltered data, the fractal dimension was estimated to be 2.45. However, with a + or - 12 sigma bandwidth, the fractal dimension increased to 2. 73.

Download or read book Numerical Simulation of Turbulent Jets with Rectangular Cross section written by Robert V. Wilson and published by . This book was released on 1997 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Investigation of Variable Momentum Flux and Density Ratios on Confined Jets in Crossflow written by and published by . This book was released on 2016 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: A full unsteady Navier Stokes Equation (NSE) solver (known as the laminar model in FLUENT) is used to simulate a confined jet in crossflow (JICF) with Reynolds numbers (Re) in the range 287-2478. Reynolds Averaged Navier Stokes (RANS) equations are used to simulate JICF with Re in the range 4930-20000. Velocity ratios range between 0.84-3.15. Results of using the SST [lower case kappa] -- [lower case omega] or Realizable [lower case kappa] -- [lower case epsilon] are presented. Comparison to experimental data provided by the Air Force Research Lab shows that both the full NSE and RANS equations compare well with experimental data. The SST [lower case kappa] -- [lower case omega] predicts higher velocities than the Realizable model. The full Navier stokes simulation captures the major JICF vortical structures including the Counter-rotating Vortex Pair (CVP), upstream and downstream shear layers, horseshoe vortices, and hanging vortices. Many of these vortical details are lost in the RANS simulation. Two parametric studies on varying density ratio and momentum flux ratio are conducted. Varying density ratio is found to have little to no effect on the jet trajectory in the near-jet region. A lower density ratio leads to a higher Re which increases unsteadiness and turbulence which leads to improved mixing. Increasing momentum flux ratio generally increases jet penetration. However, a JICF with a larger boundary layer can penetrate deeper into the crossflow than a thinner boundary layer JICF even if the momentum flux ratio is smaller. Contributions of this work include providing additional simulation data for JICF at the presented flow conditions as well as validation of two RANS turbulence models and a full Navier Stokes solver.

Download or read book A Numerical Study of Confined Turbulent Jets written by and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experimental and Numerical Investigation of Confined Coaxial Turbulent Jets written by Jeyhoon Mamaghani Khodadadi and published by . This book was released on 1986 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Investigation of Separated Transonic Turbulent Flows with a Multiple time scale Turbulence Model written by S. W. Kim and published by . This book was released on 1990 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Manipulation and Control of Jets in Crossflow written by Ann R. Karagozian and published by Springer Science & Business Media. This book was released on 2003-06-12 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental Non-Reactive Jets in Crossflow and Other Jet Systems; Background on Modeling, Dynamical Systems, and Control; Reactive Jets in Crossflow and Multiphase Jets; Controlled Jets in Crossflow and Control via Jet Systems;

Download or read book Dynamics of Quasi two dimensional Turbulent Jets written by Julien Rémy Dominique Gérard Landel and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of quasi-two-dimensional turbulent jets is relevant to chemical reactors, the coking process in oil refinement, as well as rivers flowing into lakes or oceans. In the event of a spillage of pollutants into a river, it is critical to understand how these agents disperse with the flow in order to assess damage to the environment. For such flows, characteristic streamwise and cross-stream dimensions can be much larger than the fluid-layer thickness, and so the flow develops in a confined environment. When the distance away from the discharge location is larger than ten times the fluid-layer thickness, the flow is referred to as a quasi-two-dimensional jet. From experimental observations using dyed jets and particle image velocimetry, we find that the structure of a quasi-two-dimensional jet consists of a high-speed meandering core with large counter-rotating eddies developing on alternate sides of the core. The core and eddy structure is self-similar with distance from the discharge location. The Gaussianity of the cross-stream distribution of the time-averaged velocity is due, in part, to the sinuous instability of the core. To understand the transport and dispersion properties of quasi-two-dimensional jets we use a time-dependent advection--diffusion equation, with a mixing length hypothesis accounting for the turbulent eddy diffusivity. The model is supported by experimental releases of dye in jets or numerical releases of virtual passive tracers in experimentally-measured jet velocity fields. We consider the statistical properties of this flow by releasing and then tracking large clusters of virtual particles in the jet velocity field. The probability distributions of two-point properties (such as the distance between two particles) reveal large streamwise dispersion. Owing to this streamwise dispersive effect, a significant amount of tracers can be transported faster than the speed predicted by a simple advection model. Using potential theory, we determine the flow induced by a quasi-two-dimensional jet confined in a rectangular domain. The streamlines of the induced flow predicted by the theory agree with experimental measurements away from the jet boundary. Finally, we investigate the case of a quasi-two-dimensional particle-laden jet. Depending on the bulk concentration of dense particles, we identify different flow regimes. At low concentrations, the jet features the same core and eddy structure observed without the particles, and thus quasi-two-dimensional jet theory can apply to some extent. At larger concentrations, we observe an oscillating instability of the particle-laden jet.

Download or read book Large Eddy Simulation for Incompressible Flows written by P. Sagaut and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Download or read book Numerical Investigation of Surface Curvature Effects in Compressible Turbulent Flows written by and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work has been to develop a direct numerical simulation capability for compressible, non-canonical wall-bounded flows which is directly applicable to actual flight vehicles. Data from the simulations is used to educe information about the organized motion. In the flow and bow they are affected by the extra strain rates due to concave wall curvature. A second-order finite volume approach and both fourth-order and sixth-order compact differences are available for the spatial derivatives. The algorithm allows for generalized coordinates so that simulations about complex geometries can be performed. Extensive testing was done for two subgrid-scale models, the compressible Smagoriusky and structure function models, for a supersonic boundary layer. As the subgrid-scale viscosity also behaves as an artificial viscosity for central differencing codes, the study reinforced the need for high-order dissipation models in the simulation code. Validation of the numerical method was performed for flow over a concave surface for subsonic flow in which streamwise vortices develop in the boundary-layer due to the Gortler instability. The geometry and flow conditions closely approximated the incompressible experiments of Swearingen and Blackwelder. The simulations captured the essential features of the experiments in which counter-rotating vortices developed near the wall. As these streamwise vortices develop, the laminar boundary layer on the concave wall rapidly becomes three-dimensional. Higher-momentum fluid is pulled towards the wall from the outer flow as vortices grow downstream. The low-speed fluid lying between the vortices induces low-momentum fluid away from the wall, leading to inflectional streamwise velocity profiles, in good agreement with the experiments. (AN).

Download or read book NUMERICAL STUDIES OF A TURBULENT JET IN CROSSFLOW written by Pei Yuan Tzeng and published by . This book was released on 1985 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: its viscous rate of dissipation.