Electromagnetic control of a transitional boundary layer

Electromagnetic control of a transitional boundary layer

Albrecht, T.; Grundmann, R.; Mutschke, G.; Gerbeth, G.

The stability of a transitional boundary layer controlled by a wall-parallel, streamwise oriented Lorentz force is investigated by means of direct numerical simulation. Damping of Tollmien-Schlichting waves is observed already at weak control amplitudes.
For a particular control amplitude, similar to homogeneous suction, the initial Blasius layer evolves towards an exponential velocity profile of strongly enhanced stability. Here, intermediate velocity profiles are found to have linear stability properties superior to that of the asymptotic exponential profile. Additional 3-D simulations support the 2-D results as Lorentz force control clearly damps the coherent structures of the transitional flow.
Furthermore, results to optimize the energy consumption of the control by evolutionary strategies are presented.

Keywords: MHD; Control; Boundary Layer; DNS; linear stability analysis

  • Lecture (Conference)
    Fifth international Conference on Computational Fluid Dynamics in the Process Industries, 13.-15.12.2006, Melbourne, Australia

Permalink: https://www.hzdr.de/publications/Publ-9127
Publ.-Id: 9127