小推力长时间工作固体火箭发动机C/C喉衬的烧蚀与沉积

Erosion and deposition of carbon-carbon nozzle inserts in low-thrust long-duration solid rocket motors

针对C/C喉衬喷管小推力长时间工作固体火箭发动机,分别开展了含铝、不含铝两种推进剂状态的地面试验。根据燃烧室压强及发动机推力测试曲线计算了喷管喉径的瞬变值,对比研究了喉衬的烧蚀、沉积过程,指出含铝推进剂发动机C/C喉衬先后经历初始沉积、沉积消融、持续烧蚀、烧蚀与沉积交替四个阶段,而推进剂不含铝时则没有明显的初始沉积与沉积消融。讨论了推进剂配方、燃烧室压强、喷管结构等因素对喉衬烧蚀、沉积的影响,并提出了相应的改善措施。

In order to study the erosion and deposition process of the carbon-carbon nozzle inserts in low-thrust,long-duration solid rocket applications,two motors using metallized and non-metallized propellants,respectively,were tested.The transient value of the throat diameter was obtained from the pressure and thrust measurements.It was indicated that for metallized propellant the throat experienced four stages as initial deposition,deposition melt,continuous erosion,alternately erosion and deposition,while no initial deposition and melt phenomena were observed in the non-metallized case.Some approaches to minimize throat variation were developed based upon the investigation of the effect of chamber pressure,propellant composition and nozzle configurations on the throat erosion and deposition.