摘要
为了探索近当量比极限爆震波失效过程,采用乙烯作为燃料和50%氧浓度的富氧空气作为氧化剂进行实验研究。在不同的初始压力(32、30 kPa和28 kPa)下通过调整当量比(0.6~1.4)来接近爆震传播极限,采用高速阴影测试方法以捕捉爆震波的胞格结构。结果表明:初始压力降低和当量比远离1会减小混合物的反应活性,导致化学诱导层变厚;在接近爆震传播极限时,爆震波的失效机制与横波衰减有关,混合物失去了横波的诱导作用,进而使得化学诱导层增厚,导致前导激波与反应区解耦,相应的波速降低至Chapman-Jouguet(CJ)值的70%以下;此外,诱导层厚度与速度亏损之间存在强相关性,即诱导层厚度增加使得燃烧释放的能量难以有效支撑激波运动,进而导致速度亏损增大。
To investigate detonation wave failure near the equivalence ratio limit,experiments were conducted with ethylene as fuel and 50%oxygen-enriched air as the oxidizer.The detonation limit was approached by adjusting the equivalence ratio(0.6—1.4)at different initial pressures(32 kPa,30 kPa,and 28 kPa).High-speed shadowgraphy captured the detonation waves’cellular structures.Results showed that lower initial pressures and equivalence ratios deviating from 1 decreased the mixture reactivity,leading to a larger chemical induction zone.Near detonation limits,the failure mechanism was linked to transverse wave attenuation,causing a thicker induction layer and decoupling the leading shock wave from the reaction zone.This resulted in reduced wave speed,below 70%of the Chapman-Jouguet(CJ)value.A notable correlation between induction layer thickness and velocity deficit was found:thicker induction layers hindered the combustion energy’s support for shock wave motion,causing a larger velocity deficit.
作者
杨锐
张启斌
陈庆云
范玮
YANG Rui;ZHANG Qibin;CHEN Qingyun;FAN Wei(School of Power and Energy,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《航空动力学报》
北大核心
2025年第12期215-224,共10页
Journal of Aerospace Power
基金
国家自然科学基金(52176133,52106172)
中央高校基本科研业务费项目(D5000220216)。
关键词
失效机制
高速阴影
胞格结构
化学诱导层
速度亏损
failure mechanism
high-speed shadowgraph
cellular structures
chemical induction zone
velocity deficit
