空气/煤油/水燃气发生器点火特性试验研究

燃气发生器是超燃冲压发动机地面试验系统中的关键设备，为提高系统安全性和经济性设计了空气/煤油/水燃气发生器，在富燃状态下进行了一系列点火试验，试验结果表明：该型燃气发生器，实现可靠点火的余氧系数下限为0.51；水的加入使得化学反应速率和火焰传播速度降低，燃气发生器点火和火焰稳定困难，提高余氧系数可以提高点火可靠性。同时水的加入容易引起燃烧不稳定，通过提高余氧系数可消除低频不稳定燃烧。

Experimental Researches on Ignition Characteristic of Air/Kerosene/Water Gas Generator

The gas generator is the key equipment of scramjet ground test system. A kind of air/kerosene/water gas generator was designed in order to improve the system security and economy. A series of ignition performances experiments were conducted in the fuel-rich condition with the gas generator. The experimental results indicate that: the lower limit of excess oxidizer coefficient for reliable ignition was 0.51 with the gas generator. The injection of water, which decreased the flame propagation speed and reduced the chemical reaction rate, would make it difficult to ignite and stabilize the flame. The ignition reliability could be improved by increasing excess oxidizer coefficient. Simultaneously, the injection of water would easily cause combustion instability. Low frequency combustion instability could be damped by increasing excess oxidizer coefficient.