本文首次通过实验研究了当量比和固体推进剂成分对固体火箭超燃冲压发动机富燃料混合物点火延迟时间的影响。实验模拟了马赫数为 5.5 在 23 公里处的飞行条件。当量比在 0.39-0.58 范围内进行研究，并使用了三种不同的富含固体燃料的推进剂。实验结果表明，在研究条件下，随着当量比的增加，富燃料混合气的点火延迟时间减小。这是因为富燃料混合气的质量流量和动量随着当量比的增加而增加，当当量比值越高，气体发生器中的一次燃烧效率越高。此外，固体推进剂成分在影响点火延迟方面也起着重要作用，这可能与富燃料混合物的温度和成分密切相关，温度被认为是更关键的因素。与烃基推进剂相比，使用硼基推进剂的点火延迟更短。这些结论将为缩短固体火箭超燃冲压发动机中富燃料混合物的点火延迟提供有益的指导。
In this paper, the effects of equivalence ratio and solid propellant composition on the ignition delay time of fuel-rich mixture in solid rocket scramjets were experimentally investigated for the first time. The experiments simulated a flight condition with Mach number 5.5 at 23 km. The equivalence ratio was studied in the range of 0.39–0.58, and three different solid fuel-rich propellants were used. The experimental results show that the ignition delay time of fuel-rich mixture decreases with increasing equivalence ratio under the studied conditions. This is because that the mass flow rate and momentum of the fuel-rich mixture are increasing with the equivalence ratio, and the primary combustion in the gas generator is more efficient with the higher value of equivalence ratio. Additionally, the solid propellant composition also plays an important role in influencing the ignition delay, which may be closely related to the temperature and composition of the fuel-rich mixture, with the temperature believed to be the more critical factor. Compared with hydrocarbon-based propellant, the ignition delay when using boron-based propellant is shorter. These conclusions will provide helpful guidance for shortening the ignition delay of fuel-rich mixture in solid rocket scramjets.
