脉冲爆震燃烧室内缓燃向爆震转捩数值模拟  

Numerical Simulations of Deflagration to Detonation Transition in Pulse Detonation Combustor

作　　者：赵炜 沈盈盈 杨福军[1] 张培红[1] 吴晓军[1] ZHAO Wei;SHEN Ying-ying;YANG Fu-jun;ZHANG Pei-hong;WU Xiao-jun(Computational Aerodynamic Institute of China Aerodynamic Research&Development Center,Mianyang Sichuan 621000,China)

机构地区：[1]中国空气动力研究与发展中心计算空气动力研究所,四川绵阳621000

出　　处：《航空发动机》2023年第2期55-61,共7页Aeroengine

基　　金：国家数值风洞工程(NNW);四川省科技计划(2019YJ0272)资助。

摘　　要：为了研究脉冲爆震发动机燃烧室内火焰加速及缓燃向爆震转捩过程,利用7组分8反应的氢气详细化学反应机理进行了2维数值模拟。结果表明:在火焰传播的初始阶段,障碍物、旋涡与火焰的相互作用是主导火焰加速的主要因素。在燃烧区域产生的膨胀波向前传播并诱导未燃混气流动;障碍物后的回流区及障碍物顶端脱落的旋涡使火焰面拉伸、卷曲,增加火焰面面积,同时提高燃烧放热强度,使火焰传播速度加快。在火焰发展的后期阶段,激波与障碍物的相互作用会使脱落在已燃混气中的未燃混气微团发生局部爆炸,产生新的激波进一步推动火焰加速,缩短火焰锋面与前导激波的距离。由于交错型障碍物增加了火焰传播的距离,其缓燃向爆震的转捩时间比采用对称型障碍物时的更长。To study the flame acceleration and deflagration to detonation transition in pulse detonation combustor,series of numerical simulations with hydrogen mechanism including 8 reaction steps among 7 species were performed.The results show that the interactions of obstacles,vortex and flame play a key role in the initial stage of flame acceleration.The expansion of hot gas drove the fresh gas mixture on⁃wards,the recirculation zone behind obstacles and the vortex rollup at the obstacle’s leading edges caused the flame surface to stretch and wrinkle,all these increased the exothermal strength and led to accelerating the flame velocity.At the last stage of flame acceleration,isolat⁃ed pockets of unburned fresh gas appeared in the burned gas could trigger local explosion,which is caused by the shock-obstacle interac⁃tion.And new generated shock waves further accelerated the flame,shortened the distance between flame and shock.Finally,it is found that the flame propagation distance increased could be the reason to increase DDT time in the alternate type obstacle.

关 键 词：火焰加速 缓燃 爆震 激波 燃烧室 脉冲爆震发动机 

分 类 号：V231.22[航空宇航科学与技术—航空宇航推进理论与工程]