Turbulence anisotropy and the SO(3) description

Staicu, Adrian and Vorselaars, Bart and van de Water, Willem (2003) Turbulence anisotropy and the SO(3) description. Physical Review E, 68 (4). ISSN 1539-3755

Full content URL: http://dx.doi.org/10.1103/PhysRevE.68.046303

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Abstract

We study strongly turbulent windtunnel flows with controlled anisotropy. Using a recent formalism based on angular momentum and the irreducible representations of the SO(3) rotation group, we attempt to extract this anisotropy from the angular dependence of second-order structure functions. Our instrumentation allows a measurement of both the separation and the angle dependence of the structure function. In axisymmetric turbulence which has a weak anisotropy, this more extended information produces ambiguous results. In more strongly anisotropic shear turbulence, the SO(3) description enables one to find the anisotropy scaling exponent. The key quality of the SO(3) description is that structure functions are a mixture of algebraic functions of the scale with exponents ordered such that the contribution of anisotropies diminishes at small scales. However, we find that in third-order structure functions of homogeneous shear turbulence the anisotropic contribution is always large and of the same order of magnitude as the isotropic part. Our results concern the minimum instrumentation needed to determine the parameters of the SO(3) description, and raise several questions about its ability to describe the angle dependence of high-order structure functions.

Keywords:turbulence statistics, small-scale turbulence, windtunnel experiments, anisotropic turbulence
Subjects:F Physical Sciences > F300 Physics
H Engineering > H141 Fluid Mechanics
F Physical Sciences > F310 Applied Physics
Divisions:College of Science > School of Mathematics and Physics
ID Code:18238
Deposited On:05 Aug 2015 15:57

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