Flow control effects of electromagnetic force in the boundary layer

The controlling effects of flow caused by electromagneticbody forces have been conducted. The key parameters of control experimentshave been confirmed by the theoretical analysis and the numerical simulation. Theelectrodes and the magnetic poles are flush mounted on the cylinder surfaceside by side in the order of magnet N-pole, positive(negative) electrode,magnet S-pole, negative(positive) electrode, and so on. The cylindercovered with electro-magnetic actuator is immerged in the flowingelectrolyte solution. The electromagnetic body forces, which localized onthe circular cylinder surface, have been used to modify the boundary layerof flow and control the flow flied structure. By means of theelectro-magnetic shielding and the time-region control methods, theseparation points of the circular-cylinder flow are moving between the frontstay point and the back stay point as the varieties of the space-timedistribution parameters of the electromagnetic forces, and it bringsdifferent control effects. The electromagnetic force modified on theboundary layer is convenient to controlling the flow flied structure of thecircular-cylinder flow and the cylinder wake, and it is achieved the obviouseffects of the vortex suppression and the vortex acceleration. There areprovided with the preferable effects of the oscillation absorption and thedrag reduce while the positive electromagnetic forces processed. There areexisted very strong effects of damping control while the negativeelectromagnetic forces processed, at that time the characteristics ofsymmetry and stability of the vorticity distribution on the cylinder surfaceare destroyed.