Jet Attachment Behavior using Counterflow Thrust Vectoring

A modeling and experimental study was performed to examine the jet attachment process, which can develop during the fluidic thrust vector control of subsonic and supersonic jets. Experiments performed in rectangular jets up to Mach 1.4 revealed that continuous control of jet exhaust is possible with secondary mass flow rates of the order of 1% of the primary jet mass. Under certain operating conditions, the primary jet attaches to the adjacent collar wall; model predictions agree well with measurements. The study suggests that the jet attachment process can be avoided by two principal means, namely collar truncation and pressure release.