碳氢燃料超燃冲压发动机点火技术试验

Experimental investigation of ignition technology in liquid hydrocarbon fueled scramjet combustor

关键词:  冲压喷气发动机  超音速燃烧  燃料  点火  点火器

Key words:  Ramjet engine  Supersonic combustion  Fuel  Ignition  Igniter

摘要:

在超燃冲压发动机直联式试验中,对液体碳氢燃料超声速燃烧的点火技术进行了研究,比较了多种点火方式包括氢气引导火焰点火、火炬点火器、固体装药点火器以及电火花塞的点火效果,并成功实现了氢气引导火焰与火炬点火方式下煤油的可靠着火和持续稳定燃烧,煤油当量比范围约为0 87～1 72。在氢气引导火焰点火方式中,通过增加支板和改变氢气喷注位置,可将最小氢气当量比由0 34降为0 068。通过氢气引导火焰点火和火炬点火对比试验表明在相同的燃料喷注方式和当量比下,发动机工况基本与点火方式无关。

Abstract:

Experimental investigations on the ignition technology of liquid hydrocarbon fuel in Mach 3.0 airflow were conducted using a ground direct-connect test combustor, with cross sections of 54.5×75mm. Various ignition technologies,including hydrogen pilot flames, torch igniter,solid propellant igniter and spark igniter, were tried in the test.The kerosene was ignited successfully with hydrogen pilot flames or a torch igniter, and stable combustion was sustained with fuel equivalence ratio between 0.87～1.72. The minimal required pilot hydrogen equivalence ratio was dropped from 0.34 to 0.068, when pilot hydrogen injectors were moved to the sidewalls of an additional strut from the walls of the chamber. The comparison of pilot hydrogen ignition and torch ignition shows that a stable kerosene combustion process after ignition were almost independent of different ignition methods if the injection scheme and fuel equivalence ratio were kept the same.