【摘要】 高超声速飞行使飞行器表面热负荷急剧增加,要求燃料作为推进剂供给飞行器动力的同时满足冷却要求。不同燃料的物理热沉相差无几,利用吸热型碳氢燃料的裂解反应获得热沉势在必行。在这种条件下,单纯的热裂解已不能满足要求,引发及催化裂解作为提高燃料裂解性能的途径成为研究热点。本实验分别以正十二烷、异辛烷和甲基环己烷作为模型化合物,对比了热裂解、引发裂解以及催化裂解3种不同裂解方式下模型化合物的产气率,气相产物平均分子量以及产物组成,评价不同裂解方式的裂解性能。结果表明,催化剂的使用对于提高裂解性能效果最佳,580℃下将正十二烷产气率由5.31%提高至6.94%。更多还原

【Abstract】 As flight speed increases to hypersonic regime,aerodynamic heating becomes increasingly severe,which requires using fuel not only as an energy source but also a primary coolant.In a practical view of obtaining more endothermic heat and improving the cooling capability,endothermic reactions of hydrocarbon fuel such as cracking were essential since the sensible heat sink capacities changed slightly for different hydrocarbon fuels.In this case,thermal cracking of the fuel is not enough,and cracking with initiators and catalysts are needed.In this work,an investigation was conducted to explore the thermal cracking,initiative cracking and catalytic cracking of jet fuel model compounds,n-dodecane,isooctane and methylcyclohexane.Some parameters including gas products mass fraction,the average molecular weight of gas products and major gas products distribution were measured.The results showed that model compounds cracking improved most remarkably by using catalyst,the gas products mass fraction of n-dodecane cracking from 5.31% to 6.94% at 580℃.更多还原