空气/煤油火炬点火器设计及试验

为解决超燃冲压发动机点火难题,设计了一种以空气和煤油作为氧化剂和燃料的火炬点火器。点火器能量设计为300kW,空气和煤油的设计流量分别为98.9g/s和6.7g/s。采用软件CHEMKIN4.0对不同当量比条件下点火器出口气流参数进行了计算,将点火器的工作状态优选为富氧模式。煤油从点火器端面经旋流喷嘴注入,空气分为一次喷注和二次喷注两个支路,采用普通汽车火花塞点燃空气煤油混合物。建立了试验系统,压力测量和摄影图像表明该点火器能够在当量比在0.3~1.3范围内可靠工作。点火器的起动时间约为0.9s,火焰长度约为30cm,存在高频率小幅值脉动燃烧现象。试验表明该点火器能够可靠点燃超燃冲压发动机。 

Design and experiment of air/kerosene torch igniter

An air/kerosene torch igniter was designed to solve the ignition problem of scramjet.The energy of igniter was 300kW,the mass flux of air and kerosene was 98.9g/s and 6.7g/s at design point respectively.Under different equivalence ratio (ER) conditions,the physical and chemical parameters of out-flow at the exit of igniter were computed by CHEMKIN 4.0.The working model of igniter was optimized as "oxygen-rich model".Kerosene was injected from swirl injectors at one end of igniter.Air was injected through two loops,i.e."first injector" and "second injector".The mixture of air and kerosene was ignited by a normal spark used in the car engine.The experimental system was established.The pressure measuring and photographs showed that the igniter could work reliably within ER range of 0.3-1.3.The starting time of the igniter was about 0.9 s and the length of flame was 30 cm.A pulse combustion phenomenon was represented by the high frequency and low amplitude fluctuating of pressure in igniter's combustor.Scramjet could be ignited by this igniter reliably in experiments.