【摘要】 通过数值模拟,研究了非矢量状态下(射流流流量为零)轴对称射流矢量喷管在低落压比时(NPR≤3.5),射流缝内形成的空腔流动对喷管推力特性的影响;利用这种影响来控制低落压比时喷管的气流分离位置,提高了喷管处于低落压比时的喷管推力系数;推力系数可以提高到0.90以上。因此合理布置双连通射流缝的位置,不仅有利于提高射流的推力矢量效率,而且有利于提高低落压比无次流时的推力系数,从而弥补射流矢量喷管几何固定带来的不足。更多还原

【Abstract】 To improve the thrust efficiency of the nozzle at over expanded condition(NPR≤3.5) without injection flow,the effect of the injection slots on primary flow has been studied by numerical simulation.The results indicate that the cavity flow over injection slots can change the flow separation position on the nozzle wall and increase the thrust efficiency at low NPR(nozzle pressure ratio).The thrust efficiency of the nozzle can be improved over 0.90.So To set the connected injection slots reasonably can improve the thrust efficiency with injection or without injection at low NPR.更多还原