Large Eddy Simulation of Turbulent Flow Over an Airfoil Using Unstructured Grids
Large Eddy Simulation of Turbulent Flow Over an Airfoil Using Unstructured Grids

Author: Kenneth E. Jansen

Publisher:

Published: 1999

Total Pages: 20

ISBN-13:

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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.

Large Eddy Simulation of Turbulent Flow Over an Airfoil Using Both Structured and Unstructured Grids
Large Eddy Simulation of Turbulent Flow Over an Airfoil Using Both Structured and Unstructured Grids

Author:

Publisher:

Published: 1998

Total Pages: 48

ISBN-13:

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This report describes the application of Large Eddy Simulations (LES) to turbulent flow over an airfoil. Two different approaches have been used, a second-order finite-difference solver on structured grid and a finite-element solver on unstructured grid. Results are presented for the flow around a NACA 4412 airfoil at maximum lift. The diversity of flow characteristics encountered in this flow include laminar, transitional and turbulent boundary layers, flow separation, unstable free shear layers and a wake. while Reynolds-averaged Navier-Stokes simulations (RANS) have had some success when tuned to flows dominated by one such flow characteristic, this variety of flow features taxes the presently available RANS models and presents an excellent opportunity to validate the utility of the dynamic SGS model for LES. Work has also been conducted on high order methods, both for the unstructured and the structured approach.

Direct and Large-Eddy Simulation XI
Direct and Large-Eddy Simulation XI

Author: Maria Vittoria Salvetti

Publisher: Springer

Published: 2019-02-02

Total Pages: 562

ISBN-13: 3030049159

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This book gathers the proceedings of the 11th workshop on Direct and Large Eddy Simulation (DLES), which was held in Pisa, Italy in May 2017. The event focused on modern techniques for simulating turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structures, as Direct Numerical Simulation (DNS), Large-Eddy Simulation (LES) or hybrid models based on a combination of LES and RANS approaches. In light of the growing capacities of modern computers, these approaches have been gaining more and more interest over the years and will undoubtedly be developed and applied further. The workshop offered a unique opportunity to establish a state-of-the-art of DNS, LES and related techniques for the computation and modeling of turbulent and transitional flows and to discuss about recent advances and applications. This volume contains most of the contributed papers, which were submitted and further reviewed for publication. They cover advances in computational techniques, SGS modeling, boundary conditions, post-processing and data analysis, and applications in several fields, namely multiphase and reactive flows, convection and heat transfer, compressible flows, aerodynamics of airfoils and wings, bluff-body and separated flows, internal flows and wall turbulence and other complex flows.

Direct and Large-Eddy Simulation IV
Direct and Large-Eddy Simulation IV

Author: Bernard Geurts

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 543

ISBN-13: 9401712638

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This volume contains the proceedings of the 2001 DLES4 workshop. It describes and discusses state-of-the-art modeling and simulation approaches for complex flows. Fundamental turbulence and modeling issues but also elements from modern numerical analysis are at the heart of this field of interest.

Direct and Large-Eddy Simulation IX
Direct and Large-Eddy Simulation IX

Author: Jochen Fröhlich

Publisher: Springer

Published: 2015-01-27

Total Pages: 656

ISBN-13: 3319144480

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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.

LESFOIL: Large Eddy Simulation of Flow Around a High Lift Airfoil
LESFOIL: Large Eddy Simulation of Flow Around a High Lift Airfoil

Author: Lars Davidson

Publisher: Springer Science & Business Media

Published: 2012-09-22

Total Pages: 246

ISBN-13: 3540364579

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Large Eddy Simulation is a relatively new and still evolving computatio nal strategy for predicting turbulent flows. It is now widely used in research to elucidate fundamental interactions in physics of turbulence, to predict phe nomena which are closely linked to the unsteady features of turbulence and to create data bases against which statistical closure models can be asses sed. However, its applicability to complex industrial flows, to which statisti cal models are applied routinely, has not been established with any degree of confidence. There is, in particular, a question mark against the prospect of LES becoming an economically tenable alternative to Reynolds-averaged N avier-Stokes methods at practically high Reynolds numbers and in complex geometries. Aerospace flows pose particularly challenging problems to LES, because of the high Reynolds numbers involved, the need to resolve accura tely small-scale features in the thin and often transitional boundary layers developing on aerodynamic surfaces. When the flow also contains a separated region - due to high incidence, say - the range and disparity of the influen tial scales to be resolved is enormous, and this substantially aggravates the problems of resolution and cost. It is just this combination of circumstances that has been at the heart of the project LESFOIL to which this book is devoted. The project combined the efforts, resources and expertise of 9 partner organisations, 4 universities, 3 industrial companies and 2 research institu tes.

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

Author: Ichiro Nakamori

Publisher:

Published: 2001

Total Pages: 9

ISBN-13:

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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.