基于预爆震管的旋转爆震波建立和传播过程研究

Initiation and Propagation Processes of Rotating Detonation Wave Based on Pre-Detonation Tube

为研究预爆震管点火方式下旋转爆震波的起始和传播过程,采用动态压力传感器、离子探针以及高速摄影等实验手段,分析了旋转爆震波的建立过程,探讨了预爆震管与燃烧室的相互作用,总结了预爆震管出口直径、初始填充压力以及排气时间对旋转爆震波建立和传播的影响。研究表明:由于衍射作用,从垂直安装预爆震管传出的爆震波,在燃烧室内迅速发生解耦,形成两道传播速度相同、方向相反的低速燃烧波。两道燃烧波沿燃烧室周向不断加速并对撞,对撞多次后最终发展成一道旋转爆震波。预爆震管出口直径对旋转爆震波建立时间的影响要明显大于初始填充压力的影响。增大预爆震管出口直径,可提高燃烧室内初道激波和燃烧波的强度,有利于缩短DDT时间,但由于预爆震管对旋转爆震波的传播具有一定消弱作用,旋转爆震波的平均传播速度略有减小。当预爆震管处于排气阶段时,旋转爆震波仍可稳定传播,其排气过程并不影响旋转爆震波建立时间。

Pre-detonation tubes have become a major ignition method to start rotating detonation engine(RDE).Dynamic pressure sensors,ion probes and high speed camera were adopted to study the initiation and propagation processes of rotating detonation wave(RDW)based on pre-detonation tube.The initiation processes of RDW and the interaction between pre-detonation tube and detonation combustor were investigated.The factors influencing the initiation and propagation processes of RDW,such as outlet diameter,initial filling pressure and exhausting time of the pre-detonation tube,were considered.Due to the diffraction,detonation wave from vertical-mounted pre-detonation tube would decouple in annular combustor.Two flame fronts with low speed,which had the same propagation velocity and the opposite direction of motion,were observed in the combustor.These two flame fronts accelerated along circumference of the combustor.Then a RDW appeared by many times collisions of flame fronts in the combustor.Compared with the initial filling pressure of pre-detonation tube,the outlet diameter had more impact on onset time of RDW.With the increase of outlet diameter,the onset time shortened because the incoming shock and flame enhanced,however,average propagation velocity of RDW decreased lightly because the pre-detonation tube could weaken the propagation of RDW.RDW still could propagate stably when the pre-detonation tube was still in the exhausting stages,and the onset time of RDW was independent of the exhausting process of pre-detonation tube.