铝/水两相自点火实验和理论研究  

Experimental and Theoretical Investigations on the Self-Ignition of Aluminum-Steam Two-Phase

作　　者：宋会棒 黄文林 黄佐华[1] 折勇 王立民 陈頔 张英佳[1] SONG Huibang;HUANG Wenlin;HUANG Zuohua;SHE Yong;WANG Limin;CHEN Di;ZHANG Yingjia(State Key Laboratory of Multiphase Flow Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Inner-Mongolia Power Machinery Institute,Hohhot 010010,China)

机构地区：[1]西安交通大学绿色氢电全国重点实验室,西安710049 [2]内蒙动力机械研究所,呼和浩特010010

出　　处：《西安交通大学学报》2024年第9期62-71,共10页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金“叶企孙”联合基金重点资助项目(U2141203)。

摘　　要：针对铝/水冲压发动机水蒸气氛围金属燃料点火燃烧机理不明、基础燃烧实验数据缺乏等问题,基于可视化高压激波管实验平台开展了铝/水两相自点火实验和理论研究,从发光强度及火焰图像、自点火温度和点火延迟3种角度表征了铝粉的温度效应、压力效应和尺度效应,揭示了铝/水和铝/氧点火机理的差异性,构建了铝/水自点火温度预示模型。实验结果表明:铝/水点火模式为小粒径颗粒优先着火,再引燃大粒径铝颗粒着火;临界自点火温度与铝颗粒粒径呈现反向依赖关系;点火延迟时间与温度关系符合Arrhenius关系式,颗粒越大,点火延迟的温度敏感性越高;纳米级铝粉点火延迟呈现较强的压力依赖行为,高压下火焰区域更为集中,铝粉颗粒之间竞争氧化剂更加剧烈;铝粉点火延迟的尺度效应明显,1500K下50.0μm粒径铝粉点火延迟时间约为100nm粒径铝粉的30倍。研究结果表明,铝/水自点火特性优于铝/氧,所构建的铝/水模型对微米颗粒自点火温度的预测值与文献实验值偏差较小。该研究的基础燃烧数据和点火机制理论分析可为铝/水冲压发动机的燃烧组织优化及燃烧室结构设计提供理论依据,为铝/水点火机理和模型的发展提供研究思路。In response to the problems such as unclear ignition mechanism of aluminum-steam and lack of fundamental combustion experimental data in water ramjet,this study carries out aluminum-steam two-phase self-ignition experiments and theoretical research based on the visualized high-pressure shock tube experimental platform.The temperature effect,pressure effect and scale effect of aluminum are presented from three perspectives:luminous intensity and flame image,self-ignition temperature and ignition delay time.The study reveals the difference of ignition mechanism for aluminum in steam and oxygen and develops the prediction model of aluminum-steam self-ignition temperature.The experimental results demonstrate that the ignition of aluminum-steam follows a mode where small-sized particles are preferentially ignited,subsequently the larger particles.The critical self-ignition temperature is inversely dependent on the aluminum particle size.The relation between ignition delay time and temperature conforms to the Arrhenius relation,with smaller particles exhibiting higher temperature sensitivity in ignition delay time.The ignition delay time of nano-sized aluminum powder exhibits a pronounced pressure-dependent behavior,and with the flame area exhibiting more concentrated under high pressure conditions,the oxidizer competition among aluminum powder particles is more intense.The scale effect on aluminum powder ignition delay time is obvious,and the ignition delay time of 50μm aluminum powder at 1500 K is about 30 times that of 100 nm aluminum powder.It is found that aluminum-steam self-ignition characteristic is superior to aluminum-oxygen,and the established aluminum-steam model demonstrates a minor deviation from experimental data in existing literature regarding the self-ignition temperature of micron-sized particles.The fundamental combustion data and theoretical analysis of ignition mechanism in this study offer a theoretical basis for combustion structure optimization and combustion chamber structure design of alumin

关 键 词：铝/水冲压发动机 激波管 点火延迟 点火温度 

分 类 号：TJ63[兵器科学与技术—武器系统与运用工程]