Numerical Investigation on Flow Fields of SVC Nozzle with Bypass Injection

Shock vector control (SVC) is one typical fluidic thrust vectoring technology. It has simple working principle and wide working range, but not high enough vector efficiency. In the paper, a bypass injection concept was proposed on the SVC technology to improve the vector efficiency and vector angle. The flow mechanism of SVC nozzle with bypass injection was investigated numerically after the turbulence model was validated by experimental data. The enhanced performance of SVC nozzle was estimated and the influence of critical affecting parameters, bypass injection angle ( θ.ad.) and bypass injection position (Xj.ad.) on vector performance were studied. Results show that, the vector efficiency was increased from 1.21 °/%-ω to 1.93 °/%-ω by adopting bypass injection, and the vector angle has an increase by about 58.9%. The vector performance increased with the increase of bypass injection angle when induced shock wave did not interacted with the opposite wall. The better vector performance was achieved with the configuration of the bypass injection slot was upstream of secondary injection slot when SPR is less than 1.0. In wide working ranges, a vector angle of 16°-20°, a vector efficiency larger than 2.0 ° / %-ω were obtained while thrust coefficient of a SVC nozzle kept larger than 0.90.