固液火箭发动机车轮形装药参数化设计与内弹道性能研究

Research on wagon-wheel fuel grain parametric design and internal ballistics performance of hybrid rocket motor

装药设计和内弹道性能特性研究可为固液火箭发动机的设计和优化提供基础。建立了固液火箭发动机装药设计和内弹道计算的流程与方法,根据燃面退移规律,获得了车轮形装药燃烧面积、药柱通道面积等参数随燃去肉厚的变化关系。针对给定的设计指标及动力系统方案,开展了有中心孔车轮形、无中心孔车轮形、双D形及管形装药方案设计。计算结果表明:在相同的设计要求下,车轮形装药具有更大的燃烧面积、更高的装填分数及更小的药柱长径比;管形装药的氧燃比、燃烧室压强、推力等性能参数随时间变化更小;减小药柱外径可提高管形、双D形装药的装填分数,但同时会提高药柱的长径比。研究结果对车轮形装药固液火箭发动机内弹道特性及规律的认识可起到较好的支撑作用。

The study of fuel grain design and internal ballistic performance can provide the foundation for the design and optimization of hybrid rocket motor. Fuel grain design and internal ballistics calculation process and method of hybrid rocket motor were established. Based on the fuel regression rate law, the variation relationships of burning area and fuel port area with fuel thickness of the wagon-wheel fuel grain were obtained. For certain design specifications and propulsion system scheme, fuel grain schemes were designed for wagon-wheel fuel grain with central port, wagon-wheel fuel grain without central port, double-D fuel grain, and tube fuel grain. The calculation results show that wagon-wheel fuel grain can provide larger burning area, higher propellant loading fraction, and lower length-to-diameter ratio. For tube fuel grain, variations of oxidizer-to-fuel ratio, combustion pressure and thrust with time are much less. Decreasing the fuel diameter can increase the propellant loading fraction of tube and double-D fuel grains. However, the length-to-diameter ratio increases at the same time. The results can provide a good support for the understanding of the internal ballistic characteristics and laws of hybrid rocket motors with wagon-wheel fuel grain.