六毫米内径管道中的单次爆震实验研究 *

Experimental Research on Single-Cycle Detonation in Tubes with an Inner Diameter of 6 Millimeters

关键词:  微爆震  缓燃转爆震  当量比  火焰传播  爆震压力  爆震速度

Key words:  Micro-detonation  Deflagration-to-detonation transition  Equivalence ratio  Flame propagation  Detonation pressure  Detonation velocity

摘要:

为研究微尺度下的爆震波传播特性，用乙烯和氧气为燃料和氧化剂，在6mm内径的管道内进行了爆震实验研究。实验表明，气体混合物在该尺度下可以产生稳定的爆震波，且爆震强度和火焰传播模式等受当量比影响较大。实验在不同当量比下得到了缓燃转爆震的距离，其中当量比1.4时距离最短，当量比大于2.2时爆震不稳定。用高速摄像机拍摄了当量比0.8，1.4和2.2下的火焰传播过程，发现了多种火焰形态并分析了形成原因；测量了三种当量比下的爆震速度和压力，发现当量比2.2时的爆震压力和速度最大，0.8时最小。实验值与C-J爆震理论值吻合较好。

Abstract:

To investigate the characteristics of micro-detonation waves，experiments were carried out in tubes with an inner diameter of 6mm using ethylene and oxygen as fuel and oxidizer. It shows that the gaseous mixture could successfully develop steady detonation wave. The detonation strength and flame propagation mode were greatly affected by the equivalence ratio. The distance of deflagration-to-detonation transition (DDT) was obtained at different equivalence ratios. The shortest distance occurs at equivalence ratio 1.4，and detonation becomes unsteady when equivalence ratio is greater than 2.2. The process of flame propagation was captured by high speed camera at the equivalence ratio of 0.8，1.4 and 2.2，respectively. Several kinds of flame shape were observed and the factors that influence the flame shape formation were analyzed. Detonation velocity and pressure were measured at three equivalence ratios. Results show that detonation pressure and velocity reach the maximum value at the equivalence ratio of 2.2 and the minimum value at 0.8，which is in good agreement with C-J detonation.