弯曲通道内爆震波传播特性实验研究  

Experimental study on propagation characteristics of stable detonation waves in curved channels

作　　者：曹力文 王可[2] 徐子阳 苏晓宇 范玮[1] Liwen CAO;Ke WANG;Ziyang XU;Xiaoyu SU;Wei FAN(School of Power and Energy,Northwestern Polytechnical University,Xi’an 710129,China;Shaanxi Key Laboratory of Thermal Sciences in Aeroengine System,Northwestern Polytechnical University,Xi’an 710129,China)

机构地区：[1]西北工业大学动力与能源学院,西安710129 [2]西北工业大学陕西省航空动力系统热科学重点实验室,西安710129

出　　处：《航空学报》2024年第24期179-191,共13页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52076181);陕西省创新能力支撑计划(2021KJXX-93)。

摘　　要：爆震波在弯曲通道内传播时,受通道曲率影响,在外壁面压缩与内壁面衍射共同作用下,爆震波锋面呈特定的弯曲型面,更易发生由于激波与化学反应区解耦造成的传播不稳定。为揭示爆震波在弯曲通道内的传播特性,采用C_(2)H_(4)和O_(2)/N_(2)为混合物,研究了当量比、稀释比对爆震波传播过程的影响。结果表明,在弯曲通道内,爆震波近贫燃极限与近富燃极限的熄爆机制存在差异;在富燃工况下,稀释比由0.4增大至0.6,爆震波可从规则反射传播模式转变至马赫杆增长型传播模式。通过将爆震波内壁面处的传播速度与0.8倍C-J速度进行对比,可将传播模态分为稳定传播模态、临界传播模态和不稳定传播模态;在贫燃工况下,弯曲通道内爆震波传播对稀释比变化更敏感;爆震波在封闭弯曲通道内稳定传播的临界条件是弯曲通道内壁面半径应为18.6~24.2倍的平均胞格尺寸。When detonation waves propagate in curved channels,they will be influenced by the curvature of the channel.Both the compression effect near the outer wall and the diffraction effect near the inner wall cause the detonation wave front to exhibit a certain degree of curvature,making the propagation more unstable due to decoupling between the shock wave and the chemical reaction.To clarify the propagation characteristics of detonation waves in curved channels,this study investigated the effects of the equivalence ratio and the dilution ratio on the propagation of stable detonation waves by using a mixture of ethylene,oxygen,and nitrogen.The results show that in curved channels,there are differences in the decoupling mechanism between the fuel-lean and fuel-rich conditions.Under fuel-rich conditions,as the dilution ratio varied from 0.4 to 0.6,detonation waves transitioned from the regular reflection mode to the Mach growth mode.By comparing the wave velocity on the inner wall with 0.8 times the C-J velocity,three propagation modes were observed after stable detonation waves entered the curved channel,i.e.,a stable mode,a critical mode,and an unstable mode.Under fuel-lean conditions,the dilution ratio had a more significant impact on the detonation propagation mode.The critical condition of the stable detonation mode was clarified to be that the critical inner radius should be 18.6–24.2 times of the average cell sizes.

关 键 词：弯曲通道 爆震波 当量比 稀释比 稳定模态 

分 类 号：V231.2[航空宇航科学与技术—航空宇航推进理论与工程]