Investigation on a new concept of shock vector control nozzle assisted by flashboard

To improve the vector efficiency of a shock vector control (SVC) nozzle, a new concept on SVC was proposed by introducing an assistant flashboard which helps the secondary flow to manipulate the primary flow to achieve higher vector angle. The flashboard was designed with a secondary flow tunnel inside and was arranged at the divergent section of the nozzle. In the paper, an analysis on the enhancement of the vector efficiency by adopting a flashboard was evaluated. The flow mechanim of a SVC nozzle with flashboard was investigated numerically. The influences of the critical parameters on the flowfields and vector performance of a SVC nozzle with flashboard were studied. And the results show that, compared with a SVC nozzle, the vector efficiency of a SVC nozzle with flashboard was improved by 50%-70%; the position of flashboard, the height of flashboard and secondary pressure ratio determined the configuration and position of the induced shock wave, when the induced shock wave interacted with nozzle lip, the optimal vector angle was obtained; a vector efficiency of 3.68 °/%-ω was achieved at the flashboard position of 0.70, flash height of 0.30, nozzle pressure ratio of 6 and secondary pressure ratio of 0.6.