塞式喷管冷流试验研究

结合试验喷管和试验数据,从高度补偿特性、底部气动特性、塞锥截短对性能的影响和塞式喷管流场等四方面,讨论了塞式喷管的性能和气动特点。试验结果表明:塞式喷管高度补偿效果明显,相对钟型喷管在低于设计高度上仍具有高性能;注入一定流量的二次流有利于提高塞式喷管性能,防止底部开闭过渡时推力较大幅度突降;底部二次流的注入使底部开闭过渡点的压比值升高,底部闭合后的压强值增大;塞式喷管型面设计不理想,将在流场中产生激波,降低塞式喷管的性能。

Cold flow tests of aerospike nozzles

Based on nozzle experimental data, performance and aerodynamic characteristics of the aerospike nozzles were discussed from four aspects which were altitude compensability, base aerodynamics, affection of plug truncation on performance and aerospike nozzle flowfield. The tests results indicates that aerospike nozzle has obvious capacity of altitude compensation and high efficiency under design altitude compared with bell-shaped nozzle. It is helpful to enhance aerospike nozzle performance and avoid a sudden thrust reduction at base aerodynamic transition when some base bleeding is injected. Both base transition nozzle pressure ratio and base pressure under closed base status are increased in case of some amount of base bleeding. Pressure distribution along full-length plug ramp under design altitude can provide a reference for plug truncation. The imperfect nozzle contour results in the shock wave generation in flowfield and makes the most contribution to the efficiency degradation.