不同设计型面对双钟形喷管性能影响

Influence on performance of dual-bell nozzle with different design contours

通过对室压8.5 MPa、基准喷管面积比为30、喷管总面积比100的双钟形喷管进行设计和性能分析,结果表明:喷管延伸段采用抛物线法、圆弧法、最大推力喷管型面压缩法以及等角度法四种方法设计的双钟形喷管比冲性能相差小于1 m/s,等角度法在4种设计方法中比冲性能最高;从海平面到6 km高度左右时,由于喷管延伸段会产生附加阻力损失,双钟形喷管的比冲比基准喷管的比冲平均低约1.5%左右;在飞行高度7~12 km之间,双钟形喷管出口压力低于环境压力,双钟形喷管比冲低于基准喷管,在8 km高度双钟形喷管比冲比基准喷管比冲低约9.28%;随着飞行高度的增加,从12 km左右开始,双钟型喷管的比冲高于基准喷管的比冲,到50 km后,双钟型喷管的比冲比基准喷管比冲高约10.69%。

Different dual-bell nozzles were designed with the benchmark nozzle area ratio of 30 and total nozzle area ratio of 100,and their performance were analyzed with a chamber pressure of 8.5 MPa.The results show that the difference of specific impulse performance of dual-bell nozzles designed by four methods of parabolic method, circular arc method, maximum thrust nozzle optimized with contour compression method and equal angle method is less than 1 m/s in the nozzle extension section.The specific impulse performance of equal angle method is the highest among four design methods.When the altitude is from sea level to around 6 km, the specific impulse of dual-bell nozzle is lower than the benchmark nozzle about 1.5% due to the additional drag loss caused by the nozzle extension contour.Between the flight altitudes from 7 km to 12 km, the outlet pressure of the dual-bell nozzle is lower than the ambient pressure, and the specific impulse of dual-bell nozzle is about 9.28% lower than the benchmark nozzle at the flight altitude of 8 km. As the flight altitude increases, the specific impulse of dual-bell nozzle is higher than the benchmark nozzle from 12 km. After 50 km, the specific impulse of dual-bell nozzle is about 10.69% higher than the benchmark nozzle.