连续旋转爆震波自持传播机理研究

Continuous rotating detonation engine (CRDE) could operate continuously with just one initiation, producing a roughly constant thrust, so it has huge potential benefits. However, in the CRDE, only when the fresh gas zone accumulates continuously and the detonation wave propagation velocity deficit is below the critical value can the continuous rotating detonation wave be realized. The present study concentrates on the interactions between the continuous rotating detonation wave propagation and propellant injection processes via experimental observation, theoretical analysis and numerical simulation. The accumulating mechanism of the fresh gas zone will be pointed out, the accumulating process of which will be analyzed quantitatively. Based on the observation results, the flow-field structure and propagation process of continuous rotating detonation wave will be studied quantitatively. The detonation wave propagation velocity deficit caused by the lateral expansion effect will be calculated and compared with the experimental results. The research results would contribute to the understanding of the lasting mechanism of continuous rotating detonation wave, and also have a positive effect on the continuous rotating detonation combustion control and CRDE application.

连续旋转爆震发动机（CRDE）只需一次点火即可连续爆震燃烧，能够提供稳定的推力，具有广阔的应用前景。但在CRDE中，只有在可燃气体层能够持续更新、侧向膨胀等因素引起的爆震波传播速度亏损没有达到临界值的情况下，才能够实现连续旋转爆震。本项目拟采用试验观测、理论分析、数值模拟等手段，研究连续爆震燃烧与推进剂喷注间的相互作用过程，揭示可燃气体层的形成机制，并定量分析其形成过程；定量研究连续旋转爆震波结构和瞬时传播特性，理论分析侧向膨胀所引起的传播速度亏损，并与试验统计结果进行对比。项目成果将有助于揭示连续旋转爆震波的自持传播机制，对实现连续旋转爆震燃烧控制和促进CRDE的工程应用具有重要推动作用。

通过系统试验获得了旋转爆震自持工况边界，发现当爆震波传播速度亏损大于临界值时，混合气经过上游激波不能完全燃烧，燃烧产物经过下游斜激波压缩加热后会进一步反应放热。理论预测的工况边界处侧向膨胀引起的速度亏损与临界值接近，认为侧向膨胀是旋转爆震速度亏损的主要诱因。开展了旋转爆震与来流相互作用研究，根据隔离段入、出口流动状态分成三类：超声速入流、亚声速入流、进气道受影响，总结了来流压力、温度、隔离段面积扩张比等因素的影响规律，并建立了旋转爆震对上游影响边界的理论预测模型。基于“跑道型”燃烧室开展了乙烯旋转爆震光学观测，描述了单波、预着火、下游斜激波超前等现象，实际的流场结构与现有数值模拟相比更加复杂。