A New Divergence Free Synthetic Eddy Method for the Reproduction of Inlet Flow Conditions for LES

Poletto, R.; Craft, Tim; Revell, Alistair

doi:10.1007/s10494-013-9488-2

Cited by 210 publications

(109 citation statements)

References 15 publications

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“…The latter inevitably leads to a gray zone between the LES and the RANS region. The most prominent unified hybrid approach is Detached Eddy Simulation (DES) proposed by Spalart et al [39]. Indeed, the DES of Menter and Kuntz [29,30] and Kapadia et al [20] show globally much better results than the ones provided by RANS approaches.…”

Section: Computational Grid and Boundary Conditionsmentioning

confidence: 99%

“…The solution for the Ahmed car body (as detailed in Ashton et al [19]) was to inject synthetic turbulence (via the DFSEM approach [39]) in a one-way coupled embedded DES region, thereby over-coming the lack of TKE in the initial separated shear layer. This provided the unsteady velocity fluctuations prior to the separation point, which allowed the flow to move into a fully resolved state in the initial separated shear layer.…”

Section: Embedded Lesmentioning

confidence: 99%

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Assessment of RANS and DES methods for realistic automotive models

et al. 2016

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Section: Computational Grid and Boundary Conditionsmentioning

confidence: 99%

Section: Embedded Lesmentioning

confidence: 99%

Assessment of RANS and DES methods for realistic automotive models

et al. 2016

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“…Despite positive results perhaps the most documented inherent weakness of the various forms of SEM is that the generated velocity field does not satisfy the divergence-free condition, leading to an introduction of significant pressure fluctuations at the inlet plane [71]. This can have a detrimental effect upon the development length, and expectedly pressure fluctuations are unwanted when one is concerned with noise prediction.…”

Section: Rans To Les Interfacementioning

confidence: 99%

A Review of Embedded Large Eddy Simulation for Internal Flows

Holgate

Skillen

Craft

et al. 2018

Arch Computat Methods Eng

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When scale-resolving simulation approaches are employed for the simulation of turbulent flow, computational cost can often be prohibitive. This is particularly true for internal wall-bounded flows, including flows of industrial relevances which may involve both high Reynolds number and geometrical complexity. Modelling the turbulence induced stresses (at all scales) has proven to lack requisite accuracy in many situations. In this work we review a promising family of approaches which aim to find a compromise between cost and accuracy; hybrid RANS-LES methods. We place particular emphasis on the emergence of embedded large eddy simulation. These approaches are summarised and key features relevant to internal flows are highlighted. A thorough review of the application of these methods to internal flows is given, where hybrid approaches have been shown to offer significant benefits to industrial CFD (relative to an empirical broadband modelling of turbulence). This paper concludes by providing a cost-analysis and a discussion about the emerging novel use-modalities for hybrid RANS-LES methods in industrial CFD, such as automated embedded simulation and multi-dimensional coupling.

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“…This also means that the size of the largest eddy (R max ) should be smaller than 3L z /2. Lastly, Equation (11) indicates that the directional amplitude and its sign may change randomly within the specified lower and upper limits. One of the advantages in the present SEM is that the stream of the convecting eddies is narrowed around the body of interest (aerofoil) and its vicinity only, where the size of the stream is controlled by Eq.…”

Section: Parametrisation and Definitionmentioning

confidence: 99%

“…Some of them have also been applied to compressible/aeroacoustic calculations, which can be categorised into: a) Fourier modes [1][2][3][4][5][6], b) random particle meshes [7,8] and c) synthetic eddy method (SEM) [9][10][11][12]. The Fourier-mode based approach is probably one of the most frequently attempted methods for CAA applications due to its simplicity to generate a divergence-free velocity field by taking the cross product of the wavenumber and amplitude vectors.…”

Section: Introductionmentioning

confidence: 99%

An advanced synthetic eddy method for the computation of aerofoil–turbulence interaction noise

Kim

Haeri

2015

Journal of Computational Physics

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Please cite this article in press as: J.W. Kim, S. Haeri, An advanced synthetic eddy method for the computation of aerofoil-turbulence interaction noise, J. Comput. Phys. (2015), http://dx.doi.org/10. 1016/j.jcp.2015.01.039 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThis paper presents an advanced method to synthetically generate flow turbulence via an inflow boundary condition particularly designed for threedimensional aeroacoustic simulations. The proposed method is virtually free of spurious noise that might arise from the synthetic turbulence, which enables a direct calculation of propagated sound waves from the source mechanism. The present work stemmed from one of the latest outcomes of synthetic eddy method (SEM) derived from a well-defined vector potential function creating a divergence-free velocity field with correct convection speeds of eddies, which in theory suppresses pressure fluctuations. In this paper, a substantial extension of the SEM is introduced and systematically optimised to create a realistic turbulence field based on von Kármán velocity spectra. The optimized SEM is then combined with a well-established sponge-layer technique to quietly inject the turbulent eddies into the domain from the upstream boundary, which results in a sufficiently clean acoustic field. Major advantages in the present approach are: a) that genuinely three-dimensional turbulence is generated; b) that various ways of parametrisation can be created to control/characterise the randomly distributed eddies; and, c) that its numerical implementation is efficient as the size of domain section through which the turbulent eddies should be passing can be adjusted and minimised. The performance and reliability of the proposed SEM are demonstrated by a three-dimensional simulation of aerofoil-turbulence interaction noise.

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A New Divergence Free Synthetic Eddy Method for the Reproduction of Inlet Flow Conditions for LES

Cited by 210 publications

References 15 publications

Assessment of RANS and DES methods for realistic automotive models

Assessment of RANS and DES methods for realistic automotive models

A Review of Embedded Large Eddy Simulation for Internal Flows

An advanced synthetic eddy method for the computation of aerofoil–turbulence interaction noise

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