超燃冲压发动机燃烧室新型热结构的优化设计

Optimized design on a new type thermal structure of scramjet combustor

关键词:  超燃冲压发动机  热结构  遗传算法  惰性质量  冷却液流量系数

Key words:  Scramjet  Thermal structure  Genetic algorithms  Inert mass  Coolant mass flow ratio

摘要:

为了探寻超燃冲压发动机工程设计的方法,解决超燃冲压发动机燃烧室严峻的热防护问题,设计了一种基于碳化硅陶瓷基复合材料的复合结构形式的主动冷却结构方案;建立了超燃冲压发动机燃烧室热结构设计模型和燃烧室惰性质量估算模型;基于遗传算法,以热结构各层厚度、槽宽、肋宽和肋高为待优化参数,进行了单目标和多目标优化设计。以燃烧室惰性质量最小为目标进行优化设计后,惰性质量减少了21.7%,得到最小惰性质量下的热结构尺寸;以惰性质量最小、冷却液流量系数最低为目标进行优化设计后,得到了Pareto最优前沿及对应的热结构尺寸。

Abstract:

In order to study some methods of scramjet engineering design,an active cooling thermal structure scheme based on ceramic matrix composite(CMC) is designed for scramjet combustor.Models of thermal structure design and inert mass calculation of scramjet combustor have been built up.Base on Genetic Algorithms,single-objective optimization and multi-objectives optimization have been done for thermal structure;optimized parameters include each layer thickness,trough width,rib width and rib height.According to the results of single-objective optimization,combustor mass is decreased by 21.7% and the thermal structure dimensions under minimum mass are also obtained.According to the results of multi-objectives optimization,a Pareto front is got.