Abstract: In order to make up for the deficiency of the grain of the existing single-chamber dual-thrust solid rocket motor, the new kind of combined grain composed of single center hole and multiple cambered-holes was put forward. The grain has 7 controllable variables. The curves of burning perimeter and port area versus burning web were induced through actual calculation. Parameters of interior ballistic performance of different grain types were calculated by using structure parameters of a rocket motor. Parameters of interior ballistic performance of cambered-hole grain and double composition grain were compared under the same technical requirements. The results of the calculation and design show that cambered-hole grain structure can fulfill the need of the single chamber dual-thrust rocket motor easily. In the calculation example taken in this paper, the acceleration time of the missile with porous cambered-hole grain is 75% shorter than that of the missile with star hole-single hole tube charge, the maximum speed of the missile has increased by 17%, and the speed and thrust of the missile are more stable. The new kind of grain provides a new technical way to engineering design of single chamber dual-thrust rocket motor.

Key words: Solid rocket motor;Single chamber dual-trust;Grain design;Cambered-hole;Interior ballistics

摘要： 为弥补现有单室双推力固体火箭发动机装药结构的不足，提出一种由一个中心圆孔和多个弧形内孔组成的新型单室双推力多弧形孔装药结构。该结构包含7个可控结构参数。导出了药柱燃烧周长及通气面积随燃烧肉厚变化规律的计算公式；利用火箭发动机设计结构，分析了不同参数下多弧形孔装药结构的内弹道特性；在相同技术要求下，对比了多弧形孔装药和双药型装药结构的内弹道特性参数。设计及计算结果表明，新型多孔装药结构易实现单室双推力的要求，在文中所取算例下，采用多弧形孔装药的导弹相比采用星孔-单孔管型药柱装药的导弹加速时间缩短75%，导弹最高速度提高17%，且导弹速度和推力都更加稳定。多弧形孔装药结构为单室双推力火箭发动机设计提供了一种新的技术途径。

关键词: 固体火箭发动机;单室双推力;装药设计;弧形内孔;内弹道