Flow separation control on a smooth ledge using an arc discharge in a magnetic field

Abstract

This paper presents results of experimental study for surface MHD arc actuator as vortex generator in boundary layer of smooth ledge. The study was held at flow velocities 20 to 50 m/s. The pulsed arc discharge was organized in external magnetic field. The amplitude of current was 80 A, while pulse duration was 80 μs. The flow velocity was measured by PIV method. It was founded that the location of the arc breakdown is critically impotent. The arc must be struck just above the separation point. The operation of the actuator in a pulse-periodic mode leads to a shift in the middle position of the flow separation point at frequencies up to 700 Hz and higher. A three-dimensional analysis of the separation region structure behind the MHD actuator shows that the main effect on the flow occurs in the interelectrode gap.