塞式喷管底部气动特性及其对性能的影响

在内喷管倾角为10°,20°,30°,40°和底部二次流为0.0%,0.4%,1.0%,1.4%,2.0%,3.0%的工况下,实验测量了两单元瓦状塞式喷管的底部压强。结果表明在不同的外界反压作用下,底部具有开放、闭合和开闭过渡三种气动状态,底部的这种特性不随内喷管倾角和底部二次流的变化而变化。实验研究了80%,40%,30%和20%截短两单元直排塞式喷管的高度特性,数值模拟计算了实验喷管的性能和塞锥表面的压强分布,数值模拟结果与实验测量数据吻合较好。结合实验数据和数值模拟结果分析了塞锥截短和底部气动特性对塞式喷管性能的影响。 

Base Aerodynamic Behavior and Its Effects on Performance of Aerospike Nozzle

Base pressure of a two-cell tile-shaped aerospike nozzle was measured under conditions of 10°,20°,30°,40° cell inclination and 0.0%,0.4%,1.0%,1.4%,2.0%,3.0% base bleed ratio.It was found that in the base region there exists open wake,close wake or open to close transition condition under different ambient pressure.Base aerodynamic behavior does not change with variations of cell inclination or base bleed ratio.Experimental performance change with altitude of two-cell linear aerospike nozzle truncated at 80%,40%,30% and 20% of the full plug length was obtained.The performance of the experimental aerospike nozzle and the pressure distribution along the plug were also computed.The predicted performance show good agreement with measured data.Based on experiments and numerical simulation,the effects of plug truncation and base aerodynamic behaviour on the performance of the aerospike nozzle are investigated.