Multi-axis fluidic thrust vectoring of supersonic jets via counterflow

A relatively new fluidic based technique which uses counterflow to achieve thrust vector control of supersonic jets has been examined in a series of studies for various jet geometries, namely: rectangular, axisymmetric and diamondshaped jets. In this paper, we provide a summary of these counterflow thrust vectoring experiments; some of these results have been published previously while other data are presented here for the first time. Overall, the results clearly demonstrate that single-axis (pitch) as well as multi-axis (pitch, roll and yaw) thrust vectoring can be achieved effectively by creating a secondary counterflowing stream between the primary jet and an adjacent surface. Using this technique, large deflection angles - a maximum of 20 degrees and high slew rates (180 deg./sec) were obtained with secondary mass flow rates less than 2% of the primary jet. The absence of any moving parts and the film cooling provided by the cold ambient air entrained in the secondary flow are additional features which also make this scheme very appealing.