凹腔底壁喷注煤油燃料的超燃点火试验

在来流总温为1486K、总压为1.6MPa、马赫数为2.52的条件下，采用两级串联凹腔构型燃烧室，开展了凹腔底壁喷注煤油燃料的超燃点火试验，研究了喷嘴孔径、喷注位置对点火性能的影响.结果表明:上游凹腔底壁大孔径喷嘴喷注燃料，下游凹腔点火的方案点火性能高，在煤油总体当量比为0.102~0.206范围内均可实现成功点火与稳定燃烧；燃烧反压向上游的传播过程具有明显的滞后性且与分离区的形成过程紧密耦合；燃料喷注方案决定了煤油雾化燃料场的分布，燃料的分布特征又决定了点火特征. 

Experiment on ignition of kerosene in supersonic flow based on cavity floor injection

Experiment on ignition of kerosene injected from cavity floor in scramjet combustor with two-staged cavities were conducted at the inflow conditions of Mach number of 2.52, total temperature of 1486K, total pressure of 1.6MPa. The influences of injector diameter and injection position on ignition ability were analyzed. Results showed that when kerosene was injected from the upstream cavity floor using large diameter injector and ignited by the spark in the downstream cavity, it led to a reliable ignition with large margin of flame stability (kerosene overall equivalent ratio range of 0.102-0.206). The upstream propagation of pressure disturbance had an obvious hysteresis phenomenon and interacted with the formation of separating zone. The kerosene spray distribution was governed by the fuel injection scheme, and influenced the ignition characteristics on the other hand.