Abstract: In order to explore the impact of gas temperature and working pressure on the nozzle damping characteristics of solid rocket motor，different cases were numerically studied via the pulse decay method based on the two-dimensional model of the Buffum’s motor. The aim of this study is to improve the reliability of cold flow experimental test and provide the corresponding theoretical guidance of unstable combustion research. The results indicate that the gas temperature has cooperative effects on the nozzle damping while the working pressure has little influence. After the pulse is cut off，the pressure oscillation decays faster with the gas temperature increasing，and the nozzle damping attenuation coefficient is also greater. The working pressure has little influence on the pressure oscillation decay rate，and the nozzle damping attenuation coefficient is almost unchanged under various working pressure.

Key words: Solid rocket motor；Nozzle damping；Pulse decay method；Pressure oscillation；Numerical simulation

摘要： 为探索燃气温度与燃烧室工作压强对固体火箭发动机喷管阻尼特性的影响，同时为了对冷流试验的改进及不稳定燃烧研究提供相应的理论指导，基于Buffum冷流试验发动机的二维模型，利用脉冲衰减法，开展喷管阻尼特性数值仿真计算。结果分析表明燃气温度对喷管阻尼有很大影响，而燃烧室工作压强对其几乎没有影响。燃气温度越高，切断脉冲后，压力振荡衰减越快，即喷管阻尼衰减系数越大；不同工作压强下，切断脉冲后，压力振荡衰减速度几乎不变，即发动机喷管阻尼衰减常数几乎不变。

关键词: 固体火箭发动机；喷管阻尼；脉冲衰减法；压力振荡；数值仿真