激波矢量控制喷管落压比影响矢量性能及分离区控制数值模拟

激波矢量控制喷管矢量角随落压比(NPR)的增大而下降的现象已被许多研究所证实.对NPR影响矢量角机理及基于多缝腔体和多缝辅助注气方法的分离区控制研究,目标是寻求大NPR条件下矢量性能提高的方法.研究表明:NPR影响矢量角的机理主要由于次流下游近壁面分离区由小NPR时的开放型变为大NPR时的封闭型,从而导致由于壁面压差力产生的矢量力减小所致.多缝辅助注气方法可以有效控制分离区在大NPR时保持开放,注气压力为环境压力时可以在不从系统额外引气的条件下提高矢量性能. 

Numerical simulaton of nozzle pressure ratio effect on vector performance and separation control for shock vector control nozzle

The phenomenon that vector angle of shock vector control nozzle decreases with increasing nozzle pressure ratio (NPR) has been verified by numerous researches. The study was involved with the mechanism of vector angle variation with NPR and multi-slot cavity and multi-slot assistant injection for separation control. A way for improvement of vector performance at large NPR conditions was studied. Results indicate that, the mechanism of vector angle variation with NPR is mainly due to the transition of separation region structure (from open to closed), which is located downstream the secondary injection. This leads to the reduction of thrust vector force caused by wall pressure difference. With the help of multi-slot assistant injection, the separation can be kept open at large NPR conditions. Vector performance can be improved by atmosphere pressure injection without need of bleeding air from engine.