CFD study of thrust vectoring control using a by-pass gas injection

By-pass actuators are both indispensable and critical components for thrust vector control of supersonic vehicles. Detailed flow features concerned with by-pass flow play the key role in thrust vectoring system. A computational fluid dynamics (CFD)-based study was conducted in supersonic nozzle with by-pass flow passage. To validate the numerical model, a comparison with experimental results was performed. Good agreement was observed in overall pressure distribution. Some parameters of by-pass flow should be researched for optimizing TVC performance, such as injection position, expanded ratio and secondary mass flow rate. The distance between separation point and injection position become smaller as the secondary injection position moves upstream. Significant variation of system thrust ratio and specific impulse takes place in the over expanded condition. It is indicated the secondary flow produces great effects in over expanded conditions. The separation point of boundary layer moves upstream with increasing of secondary mass flow rate. System thrust ratio and specific impulse go down with increasing secondary mass flow.