航空煤油多液滴蒸发特性实验  

Experimental study on the evaporation characteristics of aviation kerosene with multidroplets

作　　者：王方[1,2,3] 韩琪炜 李典望 金捷 WANG Fang;HAN Qiwei;LI Dianwang;JIN Jie(School of Energy and Engineering,Beihang University,Beijing 100191,China;Jiangxi Research Institute of BeiHang University,Nanchang 330096,China;Chengdu Aerodynamics Institute of Beihang University,Chengdu 611930,China)

机构地区：[1]北京航空航天大学能源与动力工程学院,北京100191 [2]北京航空航天大学江西研究院,南昌330096 [3]北航成都航空动力创新研究院,成都611930

出　　处：《清华大学学报（自然科学版）》2024年第1期63-74,共12页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金面上项目(12172345);国家自然科学基金重大研究计划项目(91741125,92041001)

摘　　要：燃烧室中燃料经喷油嘴或甩油盘等装置破碎、雾化成含有密集微小液滴的液滴群,液滴群在燃烧室的高温对流环境中先蒸发,而后与高压空气混合燃烧。该文开展了多液滴蒸发实验,旨在解决以往研究中以单液滴蒸发代替实际工况中液滴群蒸发产生的忽略液滴间相互作用的问题,为多液滴蒸发数值模拟理论提供实验数据支撑。该研究使用高速摄影机拍摄石英纤维悬挂的航空煤油液滴在高温400、500和600℃静止工况下蒸发的过程,并处理特定帧数的图片得到液滴蒸发特性曲线;多液滴蒸发实验中选择的液滴间距范围为1~4倍液滴直径。结果表明:多液滴的平均蒸发速率随着液滴间距的增大而增大,最终趋近于单液滴的平均蒸发速率,且近似成指数规律;液滴间距超过临界间距时,双液滴可看作2个独立的单液滴,此时的平均蒸发速率与单液滴平均蒸发速率基本没有区别;当2个液滴足够接近时,双液滴的平均蒸发速率降到单液滴的80%~90%。随着温度升高,液滴之间的影响距离会增大。该文得到了双液滴和三液滴蒸发的实验数据,以及双液滴关于液滴间距和温度的经验公式,实验结果与理论分析结论相吻合,为多液滴蒸发模型提供了实验数据支撑和理论创新依据。[Objective]The fuel within the combustion chamber of an aircraft engine is fragmented and atomized into a group of droplets,including dense small droplets,through devices such as fuel injectors or fuel throwers.These droplets evaporate in the high-temperature convective environment of the combustion chamber and subsequently mix with high-pressure air for combustion.Previous studies have focused on single-droplet evaporation characteristics rather than actual droplet group characteristics,thereby neglecting the interaction between droplets.To address this issue,multidroplets evaporation experiments are conducted in this study.This article provides experimental data to support the numerical simulation theory of multidroplet evaporation and accordingly supplements and corrects the droplet evaporation model.[Methods]In the multidroplet evaporation experiments,the evaporation processes of single,double,and triple jet fuel droplets suspend by quartz fiber under static conditions at high temperatures of 400,500,and 600℃are captured using a high-speed camera.Thereafter,the images are processed at a specific frame rate.A self-programming software is used to isolate the main body of the droplet,and the images are imported into MATLAB data processing software to obtain the droplet evaporation characteristic curve.Linear fitting is performed on the stable section of the evaporation characteristic curve to determine the evaporation rate of the droplet.The range of droplet spacing select in the multidroplet evaporation experiments is 1-4 times the droplet diameter.[Results]The results showed that at the same temperature,with increasing droplet spacing,the average evaporation rate of multiple droplets increased while the rate of change in evaporation rate decreased.The evaporation rate of multiple droplets tended to approach that of a single droplet and followed an approximate exponential trend.When the distance between droplets exceeded the critical distance,the mutual influence between droplets became weak enough to be igno

关 键 词：航空煤油双液滴 蒸发特性 落滴法 可变液滴间距 

分 类 号：V233.3[航空宇航科学与技术—航空宇航推进理论与工程]