A study on the thrust vector control using a bypass flow passage

Abstract

Bypass actuators are both indispensable and critical components for thrust vector control of supersonic vehicles. Detailed flow features concerned with bypass flow play a key role in thrust vectoring systems. An analytical model was created in supersonic nozzle with bypass flow passage. Meanwhile, a computational fluid dynamics-based study was conducted for studying this phenomenon. To validate the analytical and numerical models, comparisons with experimental result were performed. Good agreement was observed in overall region. Analytical and numerical pressure distributions under different injection positions were compared. The distance between separation point and injection position becomes smaller as the secondary injection position moves upstream. This is because of the reducing of bypass flow rate. The effects of expanded ratio and mass flow rate were adequately researched and tested. Significant variation of system thrust ratio and specific impulse takes place in the over-expanded conditions. It is indicated that the secondary flow produces great effects for over-expanded conditions. The separation point of boundary layer moves upstream as bypass flow rate increases. System thrust ratio and specific impulse will reduce if bypass flow rate increases.