The large-scale organized structure in free turbulent shear flow and its radiation properties

Organized structures in turbulent shear flow have been observed both in the laboratory and in the atmosphere and ocean. Recent work on modelling such structures in a temporally developing, horizontally homogeneous turbulent free shear layer (Liu & Merkine 19766) has been extended to the spatially developing mixing layer, there being no available rational transformation between the two nonlinear problems. We consider the kinetic energy development of the mean flow, large-scale structure and finegrained turbulence with a conditional average, supplementing the usual time average, to separate the non-random from the random part of the fluctuations. The integrated form of the energy equations and the accompanying shape assumptions are used to derive ‘ amplitude ’ equations for the mean flow, characterized by the shear layer thickness, the non-random and the random components of flow (which are characterized by their respective energy densities). The closure problem was overcome by the shape assumptions which entered into the interaction integrals: the instability-wavelike large-scale structure was taken to be two-dimensional and the local vertical distribution function was obtained by solving the Rayleigh equation for various local frequencies; the vertical shape of the mean stresses of the fine-grained turbulence was estimated by making use of experimental results; the vertical shapes of the wave-induced stresses were calculated locally from their corresponding equations.

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Large Scale Structures of Turbulent Shear Flow via DNS

Lecture Notes in Computer Science - High Performance Computing ◽

10.1007/978-3-540-39707-6_42 ◽

2003 ◽

pp. 468-475 ◽

Cited By ~ 5

Author(s):

Shin-ichi Satake ◽

Tomoaki Kunugi ◽

Kazuyuki Takase ◽

Yasuo Ose ◽

Norihito Naito

Keyword(s):

Shear Flow ◽

Large Scale ◽

Turbulent Shear ◽

Turbulent Shear Flow ◽

Large Scale Structures ◽

Scale Structures

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Effect of large-scale coherent structures on subgrid-scale stress and strain-rate eigenvector alignments in turbulent shear flow

Physics of Fluids ◽

10.1063/1.1890425 ◽

2005 ◽

Vol 17 (5) ◽

pp. 055103 ◽

Cited By ~ 16

Author(s):

Hyung Suk Kang ◽

Charles Meneveau

Keyword(s):

Shear Flow ◽

Strain Rate ◽

Coherent Structures ◽

Large Scale ◽

Turbulent Shear ◽

Stress And Strain ◽

Turbulent Shear Flow ◽

Subgrid Scale ◽

Stress And Strain Rate

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Sound production due to large-scale coherent structuresand identification of noise mechanisms in turbulent shear flow

10.2514/6.1979-596 ◽

1979 ◽

Author(s):

T. GATSKI

Keyword(s):

Shear Flow ◽

Coherent Structures ◽

Large Scale ◽

Sound Production ◽

Turbulent Shear ◽

Turbulent Shear Flow

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Large Scale Motions and Shear Stress Fluctuations in Turbulent Shear Flow

Volume 1A: Symposia, Part 2 ◽

10.1115/ajkfluids2015-25625 ◽

2015 ◽

Author(s):

Hinori Ito ◽

Tatsuya Tsuneyoshi ◽

Shan Feng ◽

Takahiro Ito ◽

Yoshiyuki Tsuji ◽

...

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Shear Flow ◽

Large Scale ◽

Time Lag ◽

Recirculation Region ◽

Turbulent Shear ◽

Turbulent Shear Flow ◽

Stress Fluctuation ◽

Wall Shear

We simultaneously measured the flow field and wall shear stress in a straight pipe and behind an orifice by means of particle image velocimetry (PIV) and the limiting diffusion current technique (LDCT), respectively[1]. The spatio-temporal correlation coefficients of the local vertical velocity and the shear stress fluctuations are presented, and the canonical correlations between the proper orthogonal decomposition (POD) spatial eigenmodes in the recirculation region and the wall shear stress are also discussed[2]. A response time lag occurs between the wall shear stress and the velocity field. The large canonical correlation between the POD eigenmodes and wall shear stress suggests that large-scale flow structures are important for the shear stress fluctuation. These analyses are applied to the shear flow in channel and large scale motions are studied in relation with the shear stress fluctuations.

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