A physical length-scale for LES of turbulent flow

Ugo Piomelli; B.J. Geurts

doi:10.1007/978-94-007-2482-2_3

A physical length-scale for LES of turbulent flow

Ugo Piomelli, B.J. Geurts

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

3 Citations (Scopus)

5 Downloads (Pure)

Abstract

The fundamental assumption underlying large-eddy simulations (LES) is that the large, energy-carrying, eddies are resolved, while only the smaller eddies are modeled. An implication of this assumption is that the filter-width Δ, the length scale that separates the resolved from the unresolved eddies, should be a fraction of the integral scale, which is characteristic of the large eddies. In practice, however, the filter width is taken to be proportional to the grid size, h. This approach is generally legitimate, since the grid is usually refined where the important turbulence scales are smaller; it presents, however, two problems. First, rapid variations of the mesh (especially in methods that use local mesh refinement) may cause commutation and aliasing errors, and unphysical results (Vanella et al., 2008). Second, it requires knowledge, on the part of the user, on the characteristics of turbulence; in complex flows it may not be possible to predict the turbulence behavior a priori.

Original language	English
Title of host publication	Direct and Large-Eddy Simulation VIII
Editors	Hans Kuerten, Bernard Geurts, Vincenzo Armenio, Jochen Fröhlich
Place of Publication	Dordrecht
Publisher	Springer
Pages	15-20
ISBN (Electronic)	978-94-007-2482-2
ISBN (Print)	978-94-007-2481-5
DOIs	https://doi.org/10.1007/978-94-007-2482-2_3
Publication status	Published - 2011
Event	8th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VIII, DLES 2010 - Eindhoven University of Technology, Eindhoven, Netherlands Duration: 7 Jul 2010 → 9 Jul 2010 Conference number: 8

Publication series

Name	ERCOFTAC series
Publisher	Springer
Volume	15
ISSN (Print)	1382-4309

Workshop

Workshop	8th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VIII, DLES 2010
Abbreviated title	DLES
Country/Territory	Netherlands
City	Eindhoven
Period	7/07/10 → 9/07/10

Keywords

Eddy viscosity
Integral scale
Plane channel
Integral length scale
Smagorinsky model

Access to Document

10.1007/978-94-007-2482-2_3

Cite this

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title = "A physical length-scale for LES of turbulent flow",

abstract = "The fundamental assumption underlying large-eddy simulations (LES) is that the large, energy-carrying, eddies are resolved, while only the smaller eddies are modeled. An implication of this assumption is that the filter-width Δ, the length scale that separates the resolved from the unresolved eddies, should be a fraction of the integral scale, which is characteristic of the large eddies. In practice, however, the filter width is taken to be proportional to the grid size, h. This approach is generally legitimate, since the grid is usually refined where the important turbulence scales are smaller; it presents, however, two problems. First, rapid variations of the mesh (especially in methods that use local mesh refinement) may cause commutation and aliasing errors, and unphysical results (Vanella et al., 2008). Second, it requires knowledge, on the part of the user, on the characteristics of turbulence; in complex flows it may not be possible to predict the turbulence behavior a priori.",

keywords = "Eddy viscosity, Integral scale, Plane channel, Integral length scale, Smagorinsky model",

author = "Ugo Piomelli and B.J. Geurts",

year = "2011",

doi = "10.1007/978-94-007-2482-2_3",

language = "English",

isbn = "978-94-007-2481-5",

series = "ERCOFTAC series",

publisher = "Springer",

pages = "15--20",

editor = "Hans Kuerten and Bernard Geurts and Vincenzo Armenio and Jochen Fr{\"o}hlich",

booktitle = "Direct and Large-Eddy Simulation VIII",

address = "Germany",

note = "8th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VIII, DLES 2010, DLES ; Conference date: 07-07-2010 Through 09-07-2010",

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Piomelli, U & Geurts, BJ 2011, A physical length-scale for LES of turbulent flow. in H Kuerten, B Geurts, V Armenio & J Fröhlich (eds), Direct and Large-Eddy Simulation VIII. ERCOFTAC series, vol. 15, Springer, Dordrecht, pp. 15-20, 8th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VIII, DLES 2010, Eindhoven, Netherlands, 7/07/10. https://doi.org/10.1007/978-94-007-2482-2_3

A physical length-scale for LES of turbulent flow. / Piomelli, Ugo; Geurts, B.J.
Direct and Large-Eddy Simulation VIII. ed. / Hans Kuerten; Bernard Geurts; Vincenzo Armenio; Jochen Fröhlich. Dordrecht: Springer, 2011. p. 15-20 (ERCOFTAC series; Vol. 15).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

TY - GEN

T1 - A physical length-scale for LES of turbulent flow

AU - Piomelli, Ugo

AU - Geurts, B.J.

N1 - Conference code: 8

PY - 2011

Y1 - 2011

N2 - The fundamental assumption underlying large-eddy simulations (LES) is that the large, energy-carrying, eddies are resolved, while only the smaller eddies are modeled. An implication of this assumption is that the filter-width Δ, the length scale that separates the resolved from the unresolved eddies, should be a fraction of the integral scale, which is characteristic of the large eddies. In practice, however, the filter width is taken to be proportional to the grid size, h. This approach is generally legitimate, since the grid is usually refined where the important turbulence scales are smaller; it presents, however, two problems. First, rapid variations of the mesh (especially in methods that use local mesh refinement) may cause commutation and aliasing errors, and unphysical results (Vanella et al., 2008). Second, it requires knowledge, on the part of the user, on the characteristics of turbulence; in complex flows it may not be possible to predict the turbulence behavior a priori.

AB - The fundamental assumption underlying large-eddy simulations (LES) is that the large, energy-carrying, eddies are resolved, while only the smaller eddies are modeled. An implication of this assumption is that the filter-width Δ, the length scale that separates the resolved from the unresolved eddies, should be a fraction of the integral scale, which is characteristic of the large eddies. In practice, however, the filter width is taken to be proportional to the grid size, h. This approach is generally legitimate, since the grid is usually refined where the important turbulence scales are smaller; it presents, however, two problems. First, rapid variations of the mesh (especially in methods that use local mesh refinement) may cause commutation and aliasing errors, and unphysical results (Vanella et al., 2008). Second, it requires knowledge, on the part of the user, on the characteristics of turbulence; in complex flows it may not be possible to predict the turbulence behavior a priori.

KW - Eddy viscosity

KW - Integral scale

KW - Plane channel

KW - Integral length scale

KW - Smagorinsky model

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DO - 10.1007/978-94-007-2482-2_3

M3 - Conference contribution

SN - 978-94-007-2481-5

T3 - ERCOFTAC series

SP - 15

EP - 20

BT - Direct and Large-Eddy Simulation VIII

A2 - Kuerten, Hans

A2 - Geurts, Bernard

A2 - Armenio, Vincenzo

A2 - Fröhlich, Jochen

PB - Springer

CY - Dordrecht

T2 - 8th ERCOFTAC Workshop on Direct and Large-Eddy Simulation VIII, DLES 2010

Y2 - 7 July 2010 through 9 July 2010

ER -

A physical length-scale for LES of turbulent flow

Abstract

Publication series

Workshop

Keywords

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