Turbulent structures in a non-equilibrium large-velocity-defect turbulent boundary layer

Yvan Maciel; Mark P. Simens; Ayse G. Gungor

Turbulent structures in a non-equilibrium large-velocity-defect turbulent boundary layer

Yvan Maciel, Mark P. Simens, Ayse G. Gungor

Department of Astronautical Engineering

Research output: Contribution to conference › Paper › peer-review

Abstract

The characteristics of three-dimensional intense uv coherent structures (Qs) in a strongly decelerated largevelocity-defect boundary layer are analysed by direct numerical simulation. The Reynolds number close to the exit is Re_θ =2175 and the shape factor H = 2.5. In the region of large-velocity-defect flow, the maxima of Reynolds stresses and of production of turbulent kinetic energy are located in the middle of the boundary layer. The Q2 and Q4 structures are found to be different from those of turbulent channel flows studied by Lozano-Durán et al. (J. Fluid Mech., vol. 694, 2012). They are less streamwise elongated and less present near the wall. Moreover, contrary to channel flows, wall-detached Q2 and Q4 structures are more frequent and carry a much larger amount of the Reynolds shear stress.

Original language	English
Publication status	Published - 2015
Event	9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015 - Melbourne, Australia Duration: 30 Jun 2015 → 3 Jul 2015

Conference

Conference	9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015
Country/Territory	Australia
City	Melbourne
Period	30/06/15 → 3/07/15

Cite this

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title = "Turbulent structures in a non-equilibrium large-velocity-defect turbulent boundary layer",

abstract = "The characteristics of three-dimensional intense uv coherent structures (Qs) in a strongly decelerated largevelocity-defect boundary layer are analysed by direct numerical simulation. The Reynolds number close to the exit is Reθ =2175 and the shape factor H = 2.5. In the region of large-velocity-defect flow, the maxima of Reynolds stresses and of production of turbulent kinetic energy are located in the middle of the boundary layer. The Q2 and Q4 structures are found to be different from those of turbulent channel flows studied by Lozano-Dur{\'a}n et al. (J. Fluid Mech., vol. 694, 2012). They are less streamwise elongated and less present near the wall. Moreover, contrary to channel flows, wall-detached Q2 and Q4 structures are more frequent and carry a much larger amount of the Reynolds shear stress.",

author = "Yvan Maciel and Simens, {Mark P.} and Gungor, {Ayse G.}",

year = "2015",

language = "English",

note = "9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015 ; Conference date: 30-06-2015 Through 03-07-2015",

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TY - CONF

T1 - Turbulent structures in a non-equilibrium large-velocity-defect turbulent boundary layer

AU - Maciel, Yvan

AU - Simens, Mark P.

AU - Gungor, Ayse G.

PY - 2015

Y1 - 2015

N2 - The characteristics of three-dimensional intense uv coherent structures (Qs) in a strongly decelerated largevelocity-defect boundary layer are analysed by direct numerical simulation. The Reynolds number close to the exit is Reθ =2175 and the shape factor H = 2.5. In the region of large-velocity-defect flow, the maxima of Reynolds stresses and of production of turbulent kinetic energy are located in the middle of the boundary layer. The Q2 and Q4 structures are found to be different from those of turbulent channel flows studied by Lozano-Durán et al. (J. Fluid Mech., vol. 694, 2012). They are less streamwise elongated and less present near the wall. Moreover, contrary to channel flows, wall-detached Q2 and Q4 structures are more frequent and carry a much larger amount of the Reynolds shear stress.

AB - The characteristics of three-dimensional intense uv coherent structures (Qs) in a strongly decelerated largevelocity-defect boundary layer are analysed by direct numerical simulation. The Reynolds number close to the exit is Reθ =2175 and the shape factor H = 2.5. In the region of large-velocity-defect flow, the maxima of Reynolds stresses and of production of turbulent kinetic energy are located in the middle of the boundary layer. The Q2 and Q4 structures are found to be different from those of turbulent channel flows studied by Lozano-Durán et al. (J. Fluid Mech., vol. 694, 2012). They are less streamwise elongated and less present near the wall. Moreover, contrary to channel flows, wall-detached Q2 and Q4 structures are more frequent and carry a much larger amount of the Reynolds shear stress.

UR - http://www.scopus.com/inward/record.url?scp=85034440745&partnerID=8YFLogxK

M3 - Paper

AN - SCOPUS:85034440745

T2 - 9th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2015

Y2 - 30 June 2015 through 3 July 2015

ER -

Turbulent structures in a non-equilibrium large-velocity-defect turbulent boundary layer

Abstract

Conference

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