Stabilization of magnetohydrodynamic flows by a distributed feedback system

V. V. Arsenin - E. D. Sergievskii

Abstract
It is demonstrated in the example of a tangential discontinuity between a moving perfectly conducting fluid and a nonconducting fluid at rest, both of which are ideal and incompressible, that a flow unstable under small initial perturbations in a metal-walled duct can be stabilized by the use of a special electronic circuit to excite at the fluid boundary currents that are proportional to the magnetic field perturbation at the interface. A tangential discontinuity in a conducting fluid is stabilized, as we know, by the application of a sufficiently strong steady magnetic field in the flow direction. With feedback present, stability is achieved in a weaker magnetic field. It is also shown (for long-wave oscillations) that the absence of spatial amplification of perturbations introduced in the flow with a specified frequency spectrum can be realized by a feedback system.