Large Eddy Simulation of Transonic Turbulent Flow Over an Airfoil Using a Shock Capturing Scheme with Zonal Embedded Mesh PDF Download

Author: Ichiro Nakamori
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

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Book Description
In this study, large eddy simulation(LES) of transonic flow around the NACA 0012 airfoil is performed accounting for the Leonard stress terms, the cross-stress terms and the subgrid-scale(SGS) Reynolds stress terms as the scale-similarity model at a free stream Mach number of 0.8, a Reynolds number of 9x10 (exp 6) and an angle of attack of 2.26 degrees. An upwind finite volume formulation is used for the discretization of compressible spatial-filtered Navier-Stokes equations. To exclude excessive numerical damping due to the shock-capturing scheme, a hybrid method which uses linear combination of the third order upwind scheme and the TVD scheme is employed. To reduce the total number of grid points, zonal embedded mesh is employed in the present LES analysis, in which a computational domain is decomposed near the wall-boundary. In the ease represented here, it is shown that the statistical values in the turbulent boundary layer with shock/turbulence interaction is able to be estimated, and characteristics are clarified on the statistic of the turbulence.

Author: Holger Babinsky
Publisher: Cambridge University Press
ISBN: 1139498649
Category : Technology & Engineering
Languages : en
Pages : 481

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Book Description
Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The turbulent flow over a NACA 4412 airfoil at angle of incidence corresponding to maximum lift (12 degree) has been computed via large-eddy simulation. Two different numerical approaches, one based on a conventional structured mesh and one with a more economical unstructured mesh, have been employed. Results from both simulations differ considerably from each other and from the available experimental data. Differences are found with respect to occurrence of transition near the suction peak and with respect to the amount of backflow (incipient separation) near the trailing edge. The unstructured mesh code predicts rapid boundary layer growth and separation near the trailing edge, whereas the flow remains attached in the structured mesh simulation. It was concluded that a better matching of the transition mechanism (boundary layer tripping) which was employed in the experiments is paramount for an accurate simulation of this flow and for convergence of solutions from the two codes. (AN).

Author: Kenneth E. Jansen
Publisher:
ISBN:
Category : Computational fluid dynamics
Languages : en
Pages : 20

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Book Description
Many flows of aeronautical interest have regions where turbulence has a significant effect. For many of these flows, Reynolds-averaged Navier-Stokes simulation (RANSS) techniques do not give an acceptable description of the flow. In these cases a more detailed simulation of the turbulence is required. One such detailed simulation technique, large-eddy simulation (LES) has matured to the point of application to complex flows. Historically, LES have been carried out with structured grids which suffer from two major difficulties: the extension to higher Reynolds numbers leads to an impractical number of grid points, and most real world flows are rather difficult to represent geometrically with structured grids. Unstructured-grid methods offer a release from both of these constraints. Within this sponsored research significant progress has been made towards the application of the above approach to flows of aeronautical interest.

Author: Todd Allen Simons
Publisher:
ISBN:
Category :
Languages : en
Pages : 280

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Book Description
Structured, unstructured, and zonal embedded grid finite volume formulations have been developed to solve the Favre filtered Navier-Stokes equations for performing large eddy simulation of turbulent flows. These compressible formulations were developed using a dual time stepping approach with low Mach number preconditioning. For the structured and zonal embedded grid formulations, time marching was done with either an explicit Runge-Kutta scheme or an implicit lower-upper symmetric-Gauss-Seidel scheme. For the unstructured formulation, time marching used either an explicit Runge-Kutta scheme or traditional Gauss-Seidel scheme. All codes were parallelized to reduce the overall time required for simulations. These schemes were second-order accurate in space and time. Validations were performed using laminar and turbulent incompressible benchmark flows.

Author: Jean-Pierre Chollet
Publisher: Springer Science & Business Media
ISBN: 9401156247
Category : Science
Languages : en
Pages : 436

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Book Description
Progress in the numerical simulation of turbulence has been rapid in the 1990s. New techniques both for the numerical approximation of the Navier-Stokes equations and for the subgrid-scale models used in large-eddy simulation have emerged and are being widely applied for both fundamental and applied engineering studies, along with novel ideas for the performance and use of simulation for compressible, chemically reacting and transitional flows. This collection of papers from the second ERCOFTAC Workshop on Direct and Large-Eddy Simulation, held in Grenoble in September 1996, presents the key research being undertaken in Europe and Japan on these topics. Describing in detail the ambitious use of DNS for fundamental studies and of LES for complex flows of potential and actual engineering importance, this volume will be of interest to all researchers active in the area.

Author: P. Sagaut
Publisher: Springer Science & Business Media
ISBN: 9783540263449
Category : Computers
Languages : en
Pages : 600

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Book Description
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."

Author: Johan Meyers
Publisher: Springer Science & Business Media
ISBN: 1402085788
Category : Science
Languages : en
Pages : 390

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Book Description
Computational resources have developed to the level that, for the first time, it is becoming possible to apply large-eddy simulation (LES) to turbulent flow problems of realistic complexity. Many examples can be found in technology and in a variety of natural flows. This puts issues related to assessing, assuring, and predicting the quality of LES into the spotlight. Several LES studies have been published in the past, demonstrating a high level of accuracy with which turbulent flow predictions can be attained, without having to resort to the excessive requirements on computational resources imposed by direct numerical simulations. However, the setup and use of turbulent flow simulations requires a profound knowledge of fluid mechanics, numerical techniques, and the application under consideration. The susceptibility of large-eddy simulations to errors in modelling, in numerics, and in the treatment of boundary conditions, can be quite large due to nonlinear accumulation of different contributions over time, leading to an intricate and unpredictable situation. A full understanding of the interacting error dynamics in large-eddy simulations is still lacking. To ensure the reliability of large-eddy simulations for a wide range of industrial users, the development of clear standards for the evaluation, prediction, and control of simulation errors in LES is summoned. The workshop on Quality and Reliability of Large-Eddy Simulations, held October 22-24, 2007 in Leuven, Belgium (QLES2007), provided one of the first platforms specifically addressing these aspects of LES.

Author: Eric Garnier
Publisher: Springer Science & Business Media
ISBN: 9048128196
Category : Science
Languages : en
Pages : 280

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Book Description
This book addresses both the fundamentals and the practical industrial applications of Large Eddy Simulation (LES) in order to bridge the gap between LES research and the growing need to use it in engineering modeling.

Author: M. Lesieur
Publisher: Cambridge University Press
ISBN: 9780521781244
Category : Mathematics
Languages : en
Pages : 240

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Book Description
Large-Eddy Simulations of Turbulence is a reference for LES, direct numerical simulation and Reynolds-averaged Navier-Stokes simulation.