The forces on an object in flight come from the distribution of pressure on the surface. To alter an object’s trajectory, one has to shift the pressure distribution. On subsonic and transonic aircraft, this is usually done with control surfaces like an aileron, but at supersonic speeds this can require a lot of force. The schlieren images above show an alternative approach in which a plasma actuator near the nosetip generates asymmetric forces on the cone. The actuator discharges plasma at t=0, and flow is from left to right. In the first image, the bubble of plasma is expanding on the upper side of the cone, disrupting the nearby shock wave. Over time, it moves downstream, carrying its disruption with it. The asymmetric effect of the plasma causes uneven pressures on either side of the cone that can be triggered in order to turn it in flight. (Photo credit: P. Gnemmi and C. Rey)
Controlling Supersonic Flight
