AP/HTPB推进剂内孔形状对烤燃特性的影响

为了获得固体火箭发动机的推进剂内孔形状对烤燃特性的影响，针对装填高氯酸铵/端羟基聚丁二烯(AP/HTPB)的圆形孔、星孔装药的固体火箭发动机，在基于Arrhenius定律的基础上，分别建立了对应的固体火箭发动机二维、三维非稳态烤燃模型。对上述两种装药结构的固体火箭发动机烤燃过程进行了数值模拟，分析了以上两种内孔形状对推进剂烤燃特性的影响。结果表明：固体推进剂的内孔形状在不同热载荷条件下的烤燃响应特性不同。快速烤燃条件下，内孔形状对固体火箭发动机的烤燃响应特征参数影响较小；在慢速烤燃条件下，推进剂内孔形状对推进剂着火延迟时间影响有限，对着火温度和着火位置则有显著影响。采用圆形孔装药时发生烤燃响应的着火温度较高，而采用星形孔装药时则较低；圆形孔装药时着火位置在推进剂头部内孔壁面附近，且随升温速率增大着火位置逐渐向端面移动，而星形孔装药时着火位置则位于推进剂中部的内孔壁面附近，且随升温速率的增大着火位置会出现跳跃性变化。

Study of the Effect of AP/HTPB Propellant Inner HoleShapes on the Cook-off Characteristics

To obtain the effect of inner hole shape of the propellant on the cook-off characteristics,2D and 3D unsteady cook-off models,which were based on the Arrhenius law,were established for the solid rocket motors loaded with ammonium perchlorate/terminally hydroxylated polybutadiene(AP/HTPB). Numerical simulations of the cook-off process of solid rocket motors with round-shaped and star-shoped charge configurations were carried out in an attempt to reveal the effect of the inner hole shape on the cook-off characteristics of the propellant. The results show that the inner hole shape of the propellant has little effect on the cook-off response characteristics of the motor under fast cook-off conditions. Meanuhile,the inner hole shape of the propellant has little effect on the ignition delay time of the propellant under slow cook-off conditions but has a significant effect on the ignition temperature and ignition location. The ignition temperature of round-shaped propellant is higher than that of star-shaped hole. The ignition location of the round-shaped propellant is close to the inner wall surface of the propellant head. It gradually moves towards the end with the increase of the heating rate. While the ignition position of the star-shaped hole propellant is close to the wall of the inner hole of the middle of the propellant and changes abruptly with the increase of heating rate.