单元二维直排塞式喷管冷流实验

为研究塞式喷管的高度特性和底部特性,采用高压空气为工作介质对单元直排塞式喷管进行实验.研究了底部盖板、底部二次流对性能的影响和塞锥壁面压强分布.实验结果表明:无底部盖板可提高塞式喷管低空性能2%~7%;底部二次流可提高底部压强,减少底部开闭状态转变过程带来的推力突降;底部二次流流量以1%~1.5%为宜,过大将引起喷管性能下降.本实验喷管设计点效率均超过99%,部分实验接近100%,高度补偿效果明显.

Cold-flow tests on 1-cell 2D linear plug nozzle

To know more altitude compensation and base characteristics of plug nozzle, cold-flow tests on 1-cell 2D linear plug nozzle, which utilize high pressure air as propellant were conducted. The effects on 1-cell 2D linear plug nozzle of base wall and base bleed ratio were studied. The pressure distribution on plug was also studied. The results indicate that the performance of plug nozzle can be increased 2%~7% without base wall at low altitude. The bleed can increase base pressure and decrease the variety of thrust which be caused by changing from open base to close base. It is found that 1% to 1.5% base bleed ratio is the optimum value range and the performance of plug nozzle would be decreased if base bleed ration is more than that range. The maximum nozzle efficiency of all of plug nozzle tested here are more than 99%, some of them are nearly 100%. It has good altitude compensation.