Pressure, temperature and free-flight projectile-displacement measurements during a plasma discharge generated on a supersonic projectile

The generation of a plasma discharge on a projectile surface is a way of producing a pressure imbalance in order to divert a projectile from its initial trajectory. Thus, some experiments dealing with the steering of a supersonic projectile by using a plasma actuator are presented. The plasma discharge is produced by an embedded low-voltage generator capable of delivering a power controlled electric discharge between the electrodes flush with the projectile surface. A series of experiments carried out under wind-tunnel conditions at a Mach number of 3 allows surface-pressure and temperature measurements, which are synchronised with the visualisation of the perturbation evolution along the projectile surface, the disturbance being generated by the plasma discharge. Other series of experiments realised in a shock tunnel under 2.5 km of altitude real conditions at a Mach number of 4.5 demonstrates that a plasma discharge generates the angular deviation of an explosively-formed-projectile model: 120 J of stored energy delivered in 4.5 ms in front of the ogive-cylinder junction of the projectile induces an angle of attack of 11° after the plasma-discharge generation.