Investigation on flow characteristics and performance estimation of a hybrid SVC nozzle

Higher vector efficiency of fluidic thrust vectoring (FTV) technology results in less requirement on secondary flow mass, which helps to reduce the influence of secondary flow on the performance of an aero-engine. In the paper, a new concept of FTV, named as a hybrid shock vector control (SVC) nozzle, was proposed to promote the vector efficiency of a SVC nozzle. It adopts a rotatable valve with a secondary flow injection to enhance the jet penetration, so as to improve the vector performance. The flow characteristics of a hybrid SVC nozzle were investigated numerically by solving 2D RANS equations. The influence of secondary pressure ratio (SPR) and rotatable valve angle on vector performance were conducted. Then, the coupling performance of a hybrid SVC nozzle and an aero-engine was estimated, by using the approximate model of a hybrid SVC nozzle and the performance simulation model of an aero-engine. Results show that, a desirable vector efficiency of 2.96 / %-ω (the vector angle achieved by using secondary flow of 1% of primary flow) of a hybrid SVC nozzle was obtained. In the coupling progress, when a secondary flow of 5.3% of primary flow was extracted from fan exit to a hybrid SVC nozzle, a vector angle of 14.1°, and a vector efficiency of 2.91/ %-ω were achieved. Meanwhile the thrust of the aero-engine thrust decreased by 5.6% and the specific fuel consumption (SFC) increased by 0.5%.