Effect of Secondary Flow Injection Area on Thrust Vectoring Angle in Double Throat Nozzles

The present paper discussed about the technique that can be used to vector the exhaust flow in the pitch directions with using Double Throat nozzle (DTN). Compressible and supersonic gas flow inside a Double Throat nozzle and its exhaust plume at specific nozzle pressure ratios have been numerically studied with several turbulence models. The numerical results reveal that, the SST k–ω model gave the best results compared with other models in time and accuracy. In the present research, effects of changes in injection area of secondary flow and percent of secondary mass flow rate, on performance of Double Throat nozzle and thrust vectoring system have been investigated. The predicted results show that by decreasing the value of secondary flow injection area in a case with 7% secondary injection, the thrust vector angle increase 18º to 21º and thrust vectoring efficiency will increase. But by decreasing the value of secondary flow injection area, the thrust and discharge coefficient will decrease. Also when secondary mass flow rate increases, the discharge coefficient will decrease. So that in the design of fluidic thrust vectoring with double throat nozzle, the value of secondary mass flow rate should be low.