Download or read book Numerical Investigations of Compressible Turbulent Swirling Jet Flows written by Sebastian Müller and published by . This book was released on 2007 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct and Large Eddy Simulation IX written by Jochen Fröhlich and published by Springer. This book was released on 2015-01-27 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reflects the state of the art of numerical simulation of transitional and turbulent flows and provides an active forum for discussion of recent developments in simulation techniques and understanding of flow physics. Following the tradition of earlier DLES workshops, these papers address numerous theoretical and physical aspects of transitional and turbulent flows. At an applied level it contributes to the solution of problems related to energy production, transportation, magneto-hydrodynamics and the environment. A special session is devoted to quality issues of LES. The ninth Workshop on 'Direct and Large-Eddy Simulation' (DLES-9) was held in Dresden, April 3-5, 2013, organized by the Institute of Fluid Mechanics at Technische Universität Dresden. This book is of interest to scientists and engineers, both at an early level in their career and at more senior levels.
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 Investigation of an Internal Layer in Turbulent Flow Over a Curved Hill written by S.-W. Kim and published by . This book was released on 1989 with total page 44 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 Experimental and Numerical Studies of Turbulent Swirling Jets in Ducted Streams written by and published by . This book was released on 1975 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Weakly Compressible Turbulence Using Symmetry Methods and Direct Numerical Simulation written by Raphael Gotthard Harald Arlitt and published by Cuvillier Verlag. This book was released on 2005 with total page 221 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 Experimental Investigation of Turbulent Swirling Jets written by Sara Toutiaei and published by . This book was released on 2014 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, velocity distributions of a swirling and a non-swirling jet flows were obtained using Laser Doppler Anemometer (LDA) in the near field where both jets are at the same stages of development. The resulting mean velocity and Reynolds stress distributions and the energy budgets of the axial Reynolds stresses are assessed. All Reynolds stresses showed higher magnitude in the swirling case compared to the non-swirling one at the same measurement axial locations. The swirling jet is found to exhibit larger production, mean convection and turbulence transport terms in the energy budget of axial Reynolds stress. The result shows faster development of the swirling jet compared with the non-swirling jet and is in consistency with previous studies. The turbulent transport term is found to be responsible for the faster development of the turbulence in the swirling jet.
Download or read book Turbulent Swirling Jets with Excitation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-04 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: An existing cold-jet facility at NASA Lewis Research Center was modified to produce swirling flows with controllable initial tangential velocity distribution. Two extreme swirl profiles, i.e., one with solid-body rotation and the other predominated by a free-vortex distribution, were produced at identical swirl number of 0.48. Mean centerline velocity decay characteristics of the solid-body rotation jet flow exhibited classical decay features of a swirling jet with S - 0.48 reported in the literature. However, the predominantly free-vortex distribution case was on the verge of vortex breakdown, a phenomenon associated with the rotating flows of significantly higher swirl numbers, i.e., S sub crit greater than or equal to 0.06. This remarkable result leads to the conclusion that the integrated swirl effect, reflected in the swirl number, is inadequate in describing the mean swirling jet behavior in the near field. The relative size (i.e., diameter) of the vortex core emerging from the nozzle and the corresponding tangential velocity distribution are also controlling factors. Excitability of swirling jets is also investigated by exciting a flow with a swirl number of 0.35 by plane acoustic waves at a constant sound pressure level and at various frequencies. It is observed that the cold swirling jet is excitable by plane waves, and that the instability waves grow about 50 percent less in peak r.m.s. amplitude and saturate further upstream compared to corresponding waves in a jet without swirl having the same axial mass flux. The preferred Strouhal number based on the mass-averaged axial velocity and nozzle exit diameter for both swirling and nonswirling flows is 0.4. Taghavi, Rahmat and Farokhi, Saeed Unspecified Center NASA-CR-180895, NAS 1.26:180895 NCC3-56; RTOP 505-62-21...
Download or read book Numerical Simulation of Shock Turbulent Boundary Layer Interaction written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most flows of aerodynamic interest are compressible and turbulent. However, our present knowledge on the structures and mechanisms of turbulence is mostly based on incompressible flows. In the present work, compressibility effects in turbulent, high-speed, boundary layer flows are systematically investigated using the Direct Numerical Simulation (DNS) approach. Three-dimensional, time-dependent, fully nonlinear, compressible Navier-Stokes equations were numerically integrated by high-order finite-difference methods; no modeling for turbulence is used during the solution because the available resolution is sufficient to capture the relevant scales. The boundary layer problem deals with fully-turbulent compressible flows over flat geometries. Apart from its practical relevance to technological flows, turbulent compressible boundary layer flow is the simplest experimentally realizable turbulent compressible flow. Still, measuring difficulties prohibit a detailed experimental description of the flow, especially in the near-wall region. DNS studies provide a viable means to probe the physics of compressible turbulence in this region. The focus of this work is to explore the paths of energy transfer through which compressible turbulence is sustained. The structural similarities and differences between the incompressible and compressible turbulence are also investigated. The energy flow patterns or energy cascades are found to be directly related to the evolution of vortical structures which are generated in the near-wall region. Near-wall structures, and mechanisms which are not readily accessible through physical experiments are analyzed and their critical role on the evolution and the behavior of the flow is documented extensively. Biringen, Sedat and Hatay, Ferhat F. Unspecified Center NAG1-1472...
Download or read book Turbulence and Interactions written by Michel Deville and published by Springer. This book was released on 2014-10-15 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keynote Lectures.- Some Characteristics of Non-Reacting and Reacting Low Swirl Number Jets.- Inner-Outer Interactions in Wall-Bounded Turbulence.- Turbulence Interaction with Atmospheric Physical Processes.- LES of Pulsating Turbulent Flows over Smooth and Wavy Boundaries.- Numerical Study of Turbulence-Wave Interaction.- High Reynolds Number Wall-Bounded Turbulence and a Proposal for a New Eddy-Based Model.- Regular Papers.- PANS Methodology Applied to Elliptic-Relaxation Based Eddy Viscosity Transport Model.- PIV Study of Turbulent Flow in Porous Media.- A Model for Dissipation: Cascade SDE with Markov Regime-Switching and Dirichlet Prior.- Wavelet Analysis of the Turbulent LES Data of the Lid-Driven Cavity Flow.- A Two-Phase LES Compressible Model for Plasma-Liquid Jet Interaction.- Simulation of a Fluidized Bed Using a Hybrid Eulerian-Lagrangian Method for Particle Tracking.- Wavelet-Adapted Sub-grid Scale Models for LES.- Effect of Particle-Particle Collisions on the Spatial Distribution of Inertial Particles Suspended in Homogeneous Isotropic Turbulent Flows.- Effect of Near-Wall Componental Modification of Turbulence on Its Statistical Properties.- Large-Eddy Simulation of Transonic Buffet over a Supercritical Airfoil.- Large Eddy Simulation of Coherent Structures over Forest Canopy.- Toroidal/Poloidal Modes Dynamics in Anisotropic Turbulence.- Grid Filter Modeling for Large-Eddy Simulation.- Pulsating Flow through Porous Media.- Thermodynamic Fluctuations Behaviour during a Sheared Turbulence/Shock Interaction.- LES and DES Study of Fluid-Particle Dynamics in a Human Mouth-Throat Geometry.- Viscous Drag Reduction with Surface-Embedded Grooves.- Study on the Resolution Requirements for DNS in Turbulent Rayleigh-Bénard Convection.- On the Role of Coherent Structures in a Lid Driven Cavity Flow.- Local versus Nonlocal Processes in Turbulent Flows, Kinematic Coupling and General Stochastic Processes.- Time-Resolved 3D Simulation of an Aircraft Wing with Deployed High-Lift System.- Fluid Mechanics and Heat Transfer in a Channel with Spherical and Oval Dimples.- Investigation of the Flow around a Cylinder Plate Configuration with Respect to Aerodynamic Noise Generation Mechanisms.- LES of the Flow around Ahmed Body with Active Flow Control.- Enhanced Bubble Migration in Turbulent Channel Flow by an Acceleration-Dependent Drag Coefficient.- Experimental and Numerical Study of Unsteadiness in Boundary Layer / Shock Wave Interaction.- Measurement of Particle Accelerations with the Laser Doppler Technique.- A Novel Numerical Method for Turbulent, Two-Phase Flow.- Modeling of High Reynolds Number Flows with Solid Body Rotation or Magnetic Fields.- Direct Numerical Simulation of Buoyancy Driven Turbulence inside a Cubic Cavity.- Numerical Simulations of a Massively Separated Reactive Flow Using a DDES Approach for Turbulence Modelling.- Particle Dispersion in Large-Eddy Simulations: Influence of Reynolds Number and of Subgrid Velocity Deconvolution.- Use of Lagrangian Statistics for the Direct Analysis of the Turbulent Constitutive Equation.- Numerical Simulation of Supersonic Jet Noise with Overset Grid Techniques.- Large Eddy Simulation of Turbulent Jet Flow in Gas Turbine Combustors.- Computations of the Flow around a Wind Turbine: Grid Sensitivity Study and the Influence of Inlet Conditions.- Stochastic Synchronization of the Wall Turbulence.- Large-Eddy Simulations of an Oblique Shock Impinging on a Turbulent Boundary Layer: Effect of the Spanwise Confinement on the Low-Frequency Oscillations.- Parameter-Free Symmetry-Preserving Regularization Modelling of Turbulent Natural Convection Flows.- An a Priori Study for the Modeling of Subgrid Terms in Multiphase Flows.- Computation of Flow in a 3D Diffuser Using a Two-Velocity Field Hybrid RANS/LES.- On the Dynamics of High Reynolds Number Turbulent Axisymmetric and Plane Separating/Reattaching Flows.- Numerical Simulation and Statistical Modeling of Inertial Droplet Coalescence
Download or read book Integrated Computational experimental Study of Turbulence Modification and Mixing Enhancement in Swirling Jets written by Jonathan Wayne Naughton and published by . This book was released on 2009 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Swirling jet flows have been studied experimentally and computationally and the results have been compared with theory. Three-component Laser Doppler Anemometry (LDA) measurements have been carried out for swirling jets of various strengths and swirl distributions. Radial profiles of velocity have been obtained from the jet exit to 50 diameters downstream. The experimental results are consistent with previous results and with similarity theory for weakly swirling turbulent jets. However, the parametric range and spatial domain of the current data set makes it suitable for validation. Computational simulations have also been performed using a combination of Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches. The results have been validated with experimental data and used to explore the mechanisms behind the increased mixing enhancement observed. The combined experimental/computational effort is still ongoing, but the experiences to date have demonstrated the effectiveness of such an approach.
Download or read book Turbulent Jets written by N. Rajaratnam and published by Elsevier. This book was released on 1976-01-01 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent Jets
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Investigation of an Internal Layer in Turbulent Flow Over a Curved Hill written by S. W. Kim and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
