Abstract Effects of the pipe bundles number and position on the deflagration to detonation transition (DDT) are investigated systematically for the first time in CH4–2H2–3O2 mixture. Four pressure transducers (PCB102B06) are used to obtain the average velocity by recording the time-of-arrival of the combustion wave. Meanwhile, the soot foil is employed to register the detonation cellular patterns. The results indicate that the critical pressure for DDT is reduced significantly after the pipe bundles are introduced into the tube. The optimum position for DDT occurs at position-II. At position-I, the flame acceleration is more significant for n = 4 case, no difference can be observed among n = 3, 4 and 5 cases at position-II, and the critical pressure is lower with the increases of pipe bundle number at position-III. The process of DDT closely depends on the flame jets. Finally the parameter of DH/λ is introduced to quantify the critical condition of DDT. The critical value of DH/λ nearly fluctuates around 1 at positions-I and II, and it is far greater than 1 at position-III. This indicates that in addition to the wave propagation mechanisms, the DDT regime is also closely related to the initiation process.

中文翻译：

---

在 CH4-2H2-3O2 混合物中使用管束几何形状起爆的实验研究

摘要 首次系统地研究了管束数量和位置对 CH4–2H2–3O2 混合物中爆燃到爆轰转变 (DDT) 的影响。四个压力传感器 (PCB102B06) 用于通过记录燃烧波的到达时间来获得平均速度。同时，烟灰箔被用来记录爆震蜂窝模式。结果表明，将管束引入管内后，DDT 的临界压力显着降低。DDT 的最佳位置出现在位置 II。在位置I处，n=4情况下火焰加速度更显着，在位置II处n=3、4和5情况下没有观察到差异，并且临界压力随着管束数量的增加而降低位置-III。DDT 的过程密切依赖于火焰喷射。最后引入 DH/λ 参数来量化 DDT 的临界条件。DH/λ 的临界值在 I 和 II 位几乎在 1 附近波动，在 III 位远大于 1。这表明除波传播机制外，DDT 机制也与起爆过程密切相关。