Dynamics and scaling of wall-bounded shear turbulence through the proper orthogonal decomposition

Document Type

Conference Proceeding

Publication Date

1-1-1998

Abstract

The turbulent flow close to a solid boundary is dominated by low-speed and high-speed stream wise streaks alternating in the spanwise direction. The streaks oscillate, burst into small scale structures and reform. Most of the turbulence production, maintenance and transport occurs during the breakup of the streaks, or “bursting event”. We recall how low dimensional dynamical models based on the Proper Orthogonal Decomposition (POD) reproduce this self-sustained intermittent dynamics. We also show that the fluctuating velocity, when decomposed into POD modes in the wall-normal direction, exhibits a cascade of energy toward small scales similar to the Kolmogorov energy cascade in homogeneous turbulence. More specifically, the flow is organized into families of modes. Within each family, all modes can be deduced from one another by stretching (i.e. scaling) symmetry. The spectral energy follows a well-defined decay law as the length scales are decreased.

Identifier

84959364288 (Scopus)

Publication Title

29th AIAA Fluid Dynamics Conference

External Full Text Location

https://doi.org/10.2514/6.1998-2996

First Page

1

Last Page

14

Grant

MSS89-57462

Fund Ref

National Science Foundation

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