液体火箭发动机再生冷却槽寿命预估

基于有限元热结构耦合计算结果分析了液体火箭发动机再生冷却槽的失效形式,并分别采用Porowski模型及其蠕变修正模型对冷却槽进行寿命预估.结果表明冷却槽寿命主要取决于塑性拉伸不稳定失效;蠕变对寿命有一定影响,是寿命预估不可或缺的一部分;减小外壳与内壁的温差幅值、增大每个冷却槽的肋宽比或增加冷却槽数目可以延长寿命.该寿命预估方法可用于指导可重复使用液体火箭发动机再生冷却槽设计.

Life prediction of cooling passage for reusable liquid rocket engine

The thrust chamber life is mainly limited by the cooling passage failure,which is caused by fatigue,creep rupture and plastic tensile instability.Based on the analysis of coupled heat transfer and stress,the Porowski method was taken to perform life prediction of the reusable liquid rocket engine cooling passage.The life of nozzle throat liner was mainly determined by the plastic tensile instability,whereas the effect of creep damage can not be ignored in the life prediction procedure.Reducing the temperature difference between the ligament and closeout and increasing the width ratio of each passage or the passage number were all in favor of prolonging the life of cooling passage.The method used for predicting the cooling passage life can provide reliable criterion for the design of reusable rocket engine.