织女－3主发动机的辨识仿真

IDENTIFICATION SIMULATION OF ZN-3 SUSTAINER

织女－３探空火箭飞行试验与地面试验的主发动机喉径不同。提出了用辨识仿真方法提供弹道计算所需的推力数据。利用唯一的一发有效地面实验数据，以系统辨识法确定发动机工作时推进剂的基础燃速、沿金属丝燃速、综合因子和喉径的变化规律；再确定喷管效率；最后用内弹道计算和性能计算方法确定飞行发动机的地面推力数据。飞行试验表明，计算弹道与飞行试验弹道相吻合。

The solid propellant sustainer of ZN-3 sounding rocket is a motor embedded in seven long metal fibers. The nozzle throat diameter of sustainer for flight experiment is different from the sustainer tested on the ground. In order to provide the thrust history of flight sustainer for calculating rocket trajectory, the identification simulation method of ZN-3 sustainer is presented in this paper. Firstly,the propellant basic burning rate and burning rate along metal fibers and the variation of nozzle throat diameter are determined by system identification technology according to the experimental curve (p-t) on the ground. Secondly, the nozzle thrust efficient is determined by parameter identification. Finally,the thrust history of flight sustainer is determined by interior ballistics and performance computation. The flight experimental results show that the rocket trajectory calculated is in agreement with that of ZN-3 flight experiment. It also indicates that the thrust history calculated by identification simulation is accurate. The method presented here can be applied to performance analysis of solid rocket motors.