真空条件下液滴闪蒸的非均温建模与分析  

Modeling and analysis of non-isothermal of droplet flash evaporation in vacuum environment

作　　者：杨锐[1] 林贵平[1] 柏立战[1] 陈鹏飞[2] 李龙飞[2] 孙兵[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191 [2]中国航天科技集团公司西安航天动力研究所液体火箭发动机技术重点实验室,西安710100

出　　处：《航空动力学报》2017年第5期1058-1065,共8页Journal of Aerospace Power

摘　　要：为深入揭示液滴在真空环境下的闪蒸机理,建立了真空闪蒸全过程、非均温的传热传质数学模型,获得了各时刻液滴温度场及半径,并能够追踪结冰阶段的相变界面位置.通过开展液滴闪蒸的实验研究,观察了相变前后液滴的形态变化,并对数值模型进行了验证.基于数学模型,研究了液滴初始半径、初始温度、真空舱压力和结冰过冷度对闪蒸过程的影响规律.结果表明:真空舱压力是影响闪蒸过程的主要因素,且会影响最终平衡温度;初始半径主要影响预冷和冻结时间,而初始温度和结冰过冷度主要只影响预冷时间.To reveal the mechanism of droplet flash evaporation in vacuum in depth,a complete non-isothermal model for heat and mass transfer was established.The variation of temperature field and droplet radius was solved exactly,and the accurate position of solidliquid interface in freezing stage was tracked in real time.Based on the experimental study,the change of droplet shape before and after phase change was observed,and the numerical model was validated to accurately predict the basic features of the process.The effects of initial radius,initial temperature,vacuum pressure and subcooling degree on flash evaporation were studied.Results showed that the vacuum pressure was the major factor in the whole process which would affect the final equilibrium temperature.The initial radius mainly affected the precooling and freezing time,while the initial temperature and subcooling degree only affected the precooling time.

关 键 词：闪蒸 非均温 传热传质 移动相变界面 参数效应 

分 类 号：V434.14[航空宇航科学与技术—航空宇航推进理论与工程] TK02[动力工程及工程热物理]