雾化气流脉动下乙醇喷雾旋流火焰特性  

Characteristics of ethanol spray flame under flow pulsation in swirl burner

作　　者：陈湘男 谢定江 马康 唐勇[1] 李水清 王宁飞[1] 石保禄 CHEN Xiangnan;XIE Dingjiang;MA Kang;TANG Yong;LI Shuiqing;WANG Ningfei;SHI Baolu(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;Department of Energy and Power Engineering,School of Mechanical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]北京理工大学宇航学院,北京100081 [2]清华大学机械工程学院能源与动力工程系,北京100084

出　　处：《航空动力学报》2022年第1期67-75,共9页Journal of Aerospace Power

基　　金：国家自然科学基金重大研究计划重点项目(91641204);国家自然科学基金(51676016);中国博士后科学基金(2020M680379)。

摘　　要：针对雾化气流脉动条件下乙醇喷雾旋流非稳态燃烧问题,开展了不同雾化流量下乙醇喷雾旋流火焰对雾化气流脉动响应特性的实验研究,揭示了不同脉动频率和脉宽时长下火焰长度和抬升高度的响应特性,获得了乙醇喷雾燃烧在雾化气流脉动条件下的火焰结构、温度分布等动态规律。结果表明:随着雾化流量增加,旋流火焰由附着演化为抬升;此外,雾化气流脉动影响乙醇的雾化过程,从而使附着火焰的火焰长度和抬升火焰的抬升高度发生同频振荡;在相同的实际雾化流量下,雾化气流脉动使得附着火焰平均火焰长度和抬升火焰平均抬升高度增加;同时脉动直接改变了液滴速度、尺寸和空间分布,促进了乙醇的氧化燃烧,使得整体释热率增加,而不同频率的脉动,对喷雾火焰的释热几乎无影响。The unsteady combustion behaviors of an ethanol spray flame perturbed by pulsations of different atomizing gaseous flows were investigated experimentally. By varying the atomizing gas flow rate,the responses of flame length and lift-off height to different pulsation frequencies and durations, as well as the flame structure and temperature distribution under flow pulsations,were examined. The results showed that the spray flame changed from attachment to liftoff as the atomizing flow-rate increased. The atomizing process of liquid ethanol was significantly affected by the flow pulsation, resulting in oscillations of flame length and lift-off height at the same frequency. Under the same atomizing flow rate,the average flame length of attached flame and lifting height of lift-off flame increased. The droplet velocity, size and spatial distribution dominating the mixing of ethanol spray and oxidant were directly affected by flow pulsation, resulting in an enhancement of heat-release,while the effect of pulsating frequency was less significant.

关 键 词：气流脉动 乙醇雾化 旋流火焰 火焰长度 抬升高度 

分 类 号：V231.23[航空宇航科学与技术—航空宇航推进理论与工程]