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A new strategy of turbulence control: Plane Couette flow

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A new strategy of shear flow turbulence control is proposed. It can be realised by the following steps: (i) a specially designed, non-symmetric in spanwise direction seed perturbations are imposed at the walls of the flow; (ii) the configuration of these ensures a gain of shear flow energy and the breaking of turbulence reflection symmetry -- generates spanwise mean flow; (iii) the generated flow changes the self-sustaining dynamics of turbulence and considerable reduces its level and kinetic energy production. The generated spanwise mean flow is an intrinsic, nonlinear composition of the forced turbulence and not directly introduced in the system. First of all, a model weak near-wall forcing was designed to impose in the flow the perturbations with the required characteristics. Then the efficiency of the proposed scheme has been demonstrated by the direct numerical simulation using plane Couette flow, U=(Ay,0,0), as a representative example.

Author(s):

George Khujadze    
Chair of fluid dynamics, Technical University of Darmstadt, Darmstadt
Germany

George Chagelishvili    
Abastimani Astrophysical Observatory, Ilia State University, Tbilisi
Georgia

Martin Oberlack    
Chair of fluid dynamics, Technical University of Darmstadt, Darmstadt
Germany