Boundary layer separation control by MHD interaction

Experimental study on the boundary layer control by MHD interaction was conducted, using the shock tube driven Mach 1.5 wind tunnel. The working gas of cesium seeded argon was used instead of the air in order to obtain high MHD interaction. The experiments were carried out at three conditions of no Lorentz force, the accelerating Lorentz force and the decelerating Lorentz force. It was demonstrated for the first time that the boundary layer control by the MHD interaction is possible. The significant increase of Mach number in the boundary layer was observed when the accelerating Lorentz force was applied. Furthermore, the remarkable change of Mach number profile was observed for the decelerating Lorentz force. The measured static pressure distribution for the accelerating Lorentz force was found almost the same as the one for no MHD interaction. This is explained by the decrease of static pressure due to flow acceleration by Lorentz force and by the increase of static pressure by Joule heating of gas. For the decelerating Lorentz force, the significant pressure increase was observed, and this phenomenon is similar to the one observed in the MHD power generation experiment.