Numerical Calculation of Steady Three-dimensional Turbulent Jets in Cross Flow

Numerical Calculation of Steady Three-dimensional Turbulent Jets in Cross Flow PDF Author: Ayodeji O. Demuren
Publisher:
ISBN:
Category :
Languages : en
Pages : 72

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Numerical Calculation of Steady Three-dimensional Turbulent Jets in Cross Flow

Numerical Calculation of Steady Three-dimensional Turbulent Jets in Cross Flow PDF Author: Ayodeji O. Demuren
Publisher:
ISBN:
Category :
Languages : en
Pages : 72

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Numerical Simulation of Turbulent Jets with Rectangular Cross-Section

Numerical Simulation of Turbulent Jets with Rectangular Cross-Section PDF Author: Robert V. Wilson
Publisher:
ISBN:
Category :
Languages : en
Pages : 24

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Book Description
Three-dimensional turbulent jets with rectangular cross-section are simulated with a finite-difference numerical method. The full Navier-Stokes equations are solved at low Reynolds numbers, whereas at the high Reynolds numbers filtered forms of the equations are solved along with a subgrid scale model to approximate effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporal discretization and a fourth-order compact scheme is used for spatial discretization. Computations are performed for different inlet conditions which represent different types of jet forcing. The phenomenon of axis-switching is observed, and it is confirmed that this is based on self-induction of the vorticity field. Budgets of the mean streamwise velocity show that convection is balanced by gradients of the Reynolds stresses and the pressure.

Calculation of 3D Turbulent Jets in Crossflow with a Multigrid Method and a Second-moment Closure Model

Calculation of 3D Turbulent Jets in Crossflow with a Multigrid Method and a Second-moment Closure Model PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 30

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Characteristics of 3D Turbulent Jets in Crossflow

Characteristics of 3D Turbulent Jets in Crossflow PDF Author: A. O. Demuren
Publisher:
ISBN:
Category : Multigrid methods (Numerical analysis)
Languages : en
Pages : 26

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Analysis of the Injection of a Heated Turbulent Jet Into a Cross Flow

Analysis of the Injection of a Heated Turbulent Jet Into a Cross Flow PDF Author: James Franklin Campbell
Publisher:
ISBN:
Category : Jets
Languages : en
Pages : 72

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Book Description
An investigation has been undertaken to develop a theoretical model of the incompressible jet injection process. The discharge of a turbulent jet into a cross flow was mathematically modeled by using an integral method which accounts for natural fluid mechanisms such as turbulence, entrainment, buoyancy, and heat transfer. The analytical results are supported by experimental data and demonstrate the usefulness of the theory for estimating the trajectory and flow properties of the jet for a variety of injection conditions. The capability of predicting jet flow properties, as well as two- and three- dimensional jet paths, was enhanced by obtaining the jet cross-sectional area during the solution of the conservation equations (a number of previous studies assume a specific growth for the area). Realistic estimates of temperature in the jet fluid were acquired by accounting for heat losses in the jet flow due to forced convection and to entrainment of free-stream fluid into the jet.

Modelling and Simulation of Turbulent Heat Transfer

Modelling and Simulation of Turbulent Heat Transfer PDF Author: B. Sundén
Publisher: WIT Press
ISBN: 1853129569
Category : Science
Languages : en
Pages : 361

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Book Description
Providing invaluable information for both graduate researchers and R & D engineers in industry and consultancy, this book focuses on the modelling and simulation of fluid flow and thermal transport phenomena in turbulent convective flows. Its overall objective is to present state-of-the-art knowledge in order to predict turbulent heat transfer processes in fundamental and idealized flows as well as in engineering applications. The chapters, which are invited contributions from some of the most prominent scientists in this field, cover a wide range of topics and follow a unified outline and presentation to aid accessibility.

Computations of Complex Three-Dimensional Turbulent Free Jets

Computations of Complex Three-Dimensional Turbulent Free Jets PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723544934
Category :
Languages : en
Pages : 218

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Book Description
Three-dimensional, incompressible turbulent jets with rectangular and elliptical cross-sections are simulated with a finite-difference numerical method. The full Navier- Stokes equations are solved at low Reynolds numbers, whereas at high Reynolds numbers filtered forms of the equations are solved along with a sub-grid scale model to approximate the effects of the unresolved scales. A 2-N storage, third-order Runge-Kutta scheme is used for temporary discretization and a fourth-order compact scheme is used for spatial discretization. Although such methods are widely used in the simulation of compressible flows, the lack of an evolution equation for pressure or density presents particular difficulty in incompressible flows. The pressure-velocity coupling must be established indirectly. It is achieved, in this study, through a Poisson equation which is solved by a compact scheme of the same order of accuracy. The numerical formulation is validated and the dispersion and dissipation errors are documented by the solution of a wide range of benchmark problems. Three-dimensional computations are performed for different inlet conditions which model the naturally developing and forced jets. The experimentally observed phenomenon of axis-switching is captured in the numerical simulation, and it is confirmed through flow visualization that this is based on self-induction of the vorticity field. Statistical quantities such as mean velocity, mean pressure, two-point velocity spatial correlations and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stresses are presented. Detailed budgets of the mean momentum and Reynolds stress equations are presented to aid in the turbulence modeling of complex jets. Simulations of circular jets are used to quantify the effect of the non-uniform curvature of the non-circular jets. Wilson, Robert V. and Demuren, Ayodeji O. Langley Research Center NASA-CR-203976, NAS 1.26:203976, ICAM-97-101 NCC1-232...

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

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Turbulent Shear Flows I

Turbulent Shear Flows I PDF Author: F. Durst
Publisher: Springer Science & Business Media
ISBN: 3642463959
Category : Technology & Engineering
Languages : en
Pages : 415

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Book Description
The present book contains papers that have been selected from contributions to the First International Symposium on Turbulent Shear Flows which was held from the 18th to 20th April 1977 at The Pennsylvania State University, University Park, Pennsylvania, USA. Attend ees from close to 20 countries presented over 100 contributions at this meeting in which many aspects of the current activities in turbulence research were covered. Five topics received particular attention at the Symposium: Free Flows Wall Flows Recirculating Flows Developments in Reynolds Stress Closures New Directions in Modeling This is also reflected in the five chapters of this book with contributions from research workers from different countries. Each chapter covers the most valuable contributions of the conference to the particular chapter topic. Of course, there were many additional good con tributions to each subject at the meeting but the limitation imposed on the length of this volume required that a selection be made. The realization of the First International Symposium on Turbulent Shear Flows was p- sible by the general support of: U. S. Army Research Office U. S. Navy Research Office Continuing Education Center of The Pennsylvania State University The conference organization was carried out by the organizing committee consisting of: F. Durst, Universitat Karlsruhe, Karlsruhe, Fed. Rep. of Germany V. W. Goldschmidt, Purdue University, West Lafayette, Ind. , USA B. E. Launder, University of California, Davis, Calif. , USA F. W. Schmidt, Pennsylvania State University, University Park, Penna.

Calculation of a Circular Jet in Crossflow with a Multiple-Time-Scale Turbulence Model

Calculation of a Circular Jet in Crossflow with a Multiple-Time-Scale Turbulence Model PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781729123546
Category : Science
Languages : en
Pages : 36

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Book Description
Numerical calculation of a three dimensional turbulent flow of a jet in a crossflow using a multiple time scale turbulence model is presented. The turbulence in the forward region of the jet is in a stronger inequilibrium state than that in the wake region of the jet, while the turbulence level in the wake region is higher than that in the front region. The calculated flow and the concentration fields are in very good agreement with the measured data, and it indicated that the turbulent transport of mass, concentration, and momentum is strongly governed by the inequilibrium turbulence. The capability of the multiple time scale turbulence model to resolve the inequilibrium turbulence field is also discussed. Kim, S.-W. and Benson, T. J. Glenn Research Center NCC3-180; RTOP 505-62-52...