固体火箭发动机喷管阻尼特性的数值仿真

为了探究影响固体火箭发动机喷管阻尼特性的关键因素，基于典型柱状装药固体火箭发动机二维简化模型，利用脉冲衰减法，开展喷管阻尼特性数值仿真计算，研究了喉通比和燃烧室长度对喷管阻尼常数的影响规律，结果发现数值模拟结果与经验公式理论预估结果有较好的一致性，证实了该数值方法的有效性；在此基础上，进一步探讨了无法由经验公式直接获知的诸如喷管收敛半角以及收敛型面对喷管阻尼常数的影响规律，结果表明:收敛半角对喷管阻尼常数有很大的影响，在设计范围内，较小的收敛角有益于提高喷管阻尼特性；收敛段型面对喷管阻尼也有一定的影响，凸型型面阻尼特性优于锥型型面，锥形型面优于凹形型面. 

Numerical simulation of nozzle damping characteristics in solid rocket motor

For the purpose of investigating the key factors affecting the nozzle damping characteristics of solid rocket motor, numerical simulation of nozzle damping characteristics were carried out to study the influence of the nozzle throat area-to-grain port area ratio and the chamber length, based on the simplified two-dimensional model of the typical columnar grain of solid rocket motor and with use of pulse attenuation method.It was found that the numerical simulation results and empirical formulas theoretical estimate values were in good agreement, confirm the validity of the numerical methods; the study further explored what the empirical formula cannot deal with well, such as the change rules of nozzle convergent half-angle and nozzle convergent surface. The results show that the nozzle convergent half angle plays a vital role in nozzle damping constant. Small convergent half angle is beneficial to the nozzle damping; the convex nozzle provides more damping than the conical nozzle, which in turn provides more damping than the concave nozzle.