氢燃料缓燃向爆震转捩过程中波与火焰的匹配特性

为了解氢燃料爆震过程中压力波与火焰之间相互匹配的特性,在60mm60mm2000mm 方爆震管内,用氢气和空气混合物进行了单爆震性能研究。在爆震转捩区内布置压力传感器与离子探针,用来监控压力波和火焰的信号,同时利用高速摄影仪集中拍摄转捩区域。根据压力波和火焰面在爆震管不同时刻的强度特性、速度特性及位置特性来分析爆震过程中波与火焰匹配的规律。结果表明:压力波和火焰的强度呈现为相互正反馈匹配性质;缓燃向爆震转捩(DDT)过程中,压力波和火焰的速度表现为相互交替的变化过程,且缓燃阶段中火焰速度的增幅大于压力波速度的增幅;当火焰面追赶上激波时,产生过爆,火焰面会临时位于激波前面;在过爆衰减为正常爆震波的过程中,激波在火焰前面。

Matching characteristics of wave and flame in the deflagration to detonation transition process

A series of single-shot detonation experiments were performed to understand the matching characteristics of wave and flame in DDT for H2/air mixures in a 60mm square tube that was 2m in length.The ion-probes and pressure transducers were respectively utilized to get the signal of flame and wave,and high-speed digital imaging was used to track flame propagation of DDT area.The matching rule of shock-flame was achieved by analyzing the intensity、velocity and position characteristics of wave and flame in different time along the tube.The results indicate that intensity of wave and flame is positive feedback characteristic and the velocity of wave and flame is alternant change process.The speed amplitude of flame is rapid than that of wave in deflagration phase.This result in the overdrivern detonation wave form and flame is temporarily in front of flame when flame catch up wave.Shock is in front of flame in phase which the overdrivern detonation evolve into steady detonation wave.