This work reports the experimental characterization of detonation initiation modes in a confined chamber in respect to the different types of reacting waves generated in various small-diameter ignition tubes. Depending on the length of the tube and mixtures composition, four types of reacting waves can be generated and utilized to initiate detonation in the main chamber, namely the over-driven detonation ignition wave, CJ detonation ignition wave, high-speed deflagration ignition wave and deflagration ignition wave. Based on the mechanisms of detonation initiation in the main chamber, four initiation modes can be observed: the direct initiation, the local explosion initiation, and the fast and slow deflagration-to-detonation transition (DDT) initiation. By comparing the detonation initiation positions and flame-tip velocities, the first two modes show appreciably shorter initiation distances compared to the DDT modes. The over-driven detonation ignition wave is shown to yield a high probability of direct initiation, while contrary to expectation, the high-speed deflagration ignition wave exhibits superior initiation performance compared to the CJ detonation ignition wave. It is illustrated that the energy decay through diffraction and the effect of precursor shock wave reflection on the wall of the rectangular chamber are viable factors responsible for this observation. The deflagration ignition wave is also shown to be able to rapidly initiate the detonation near the inlet of the chamber, albeit with a lower success rate.

这项工作报告了在密闭室内的爆炸起爆模式的实验特征，这些爆炸起爆模式是针对在各种小直径点火管中产生的不同类型的反应波的。根据管的长度和混合物的组成，可以产生四种类型的反应波，并利用它们在主腔室内引发爆炸，即过驱动引爆点火波，CJ引爆点火波，高速爆燃引爆波和爆燃点火波。基于主室中爆炸起爆的机制，可以观察到四种起爆模式：直接起爆，局部爆炸起爆以及快速和缓慢的爆燃-起爆转变（DDT）起爆。通过比较起爆起始位置和火焰速度，与DDT模式相比，前两种模式显示的启动距离明显较短。过度驱动的爆燃点火波显示出很高的直接起爆可能性，而与预期相反，与CJ爆燃点火波相比，高速爆燃点火波表现出更出色的起爆性能。可以看出，通过衍射的能量衰减以及矩形腔室壁上前体冲击波反射的影响是造成这种现象的可行因素。爆燃点火波也显示出能够在腔室的入口附近迅速引发爆炸，尽管成功率较低。过度驱动的爆燃点火波显示出很高的直接起爆可能性，而与预期相反，与CJ爆燃点火波相比，高速爆燃点火波表现出更出色的起爆性能。可以看出，通过衍射的能量衰减以及矩形腔室壁上前体冲击波反射的影响是造成这种现象的可行因素。爆燃点火波也显示出能够在腔室的入口附近迅速引发爆炸，尽管成功率较低。过度驱动的爆燃点火波显示出很高的直接起爆可能性，而与预期相反，与CJ爆燃点火波相比，高速爆燃点火波表现出更出色的起爆性能。可以看出，通过衍射的能量衰减和矩形腔室壁上前体冲击波反射的影响是造成这种现象的可行因素。爆燃点火波也显示出能够在腔室的入口附近迅速引发爆炸，尽管成功率较低。可以看出，通过衍射的能量衰减以及矩形腔室壁上前体冲击波反射的影响是造成这种现象的可行因素。爆燃点火波也显示出能够在腔室的入口附近迅速引发爆炸，尽管成功率较低。可以看出，通过衍射的能量衰减以及矩形腔室壁上前体冲击波反射的影响是造成这种现象的可行因素。爆燃点火波也显示出能够在腔室的入口附近迅速引发爆炸，尽管成功率较低。