摘要
固体火箭发动机内微米级熔融态氧化铝通常会撞击燃烧室内壁面,由于氧化铝液滴具有较高的熔点,采用铝液滴替代氧化铝液滴进行实验研究。基于网格自适应技术,利用VOF方法对铝液滴撞击壁面实验进行数值计算,验证数值计算准确性。利用验证的模型开展微米量级的氧化铝液滴与壁面碰撞过程的数值模拟。研究结果表明,数值计算过程与实验基本保持一致;随着初始碰撞速度的增大,氧化铝液滴撞击壁面后依次出现反弹、附壁和破碎现象;随着氧化铝液滴粒径的增大,液滴反弹与附壁之间、附壁与破碎之间的转换临界We数随之减小; 20、50、100μm的氧化铝液滴垂直撞击固体水平壁面反弹和吸附的临界We数为170、84、50; 50μm和100μm的氧化铝液滴附壁与破碎之间的转换临界We数为141和129;液滴破碎须具备足够的动能来克服粘性耗散能和表面能。
The micrometer-size alumina droplets usually impact on the wall of solid rocket motor during combustion process. Considering the high melting point of alumina,the droplet-wall impingement experiments were carried out by the molten aluminum as a demonstration.The volume of fluid (VOF)and adaptive grid methods have been used to numerically simulate the aluminum droplet-wall impingement experiments,which have been used to validate the numerical models.The deformation process of micrometer-size alumina droplets that impacted on the wall have been calculated by the validated model under different droplet velocities and sizes.The results show that the numerical simulation process is basically in accordance with the experiment.With the increase of the initial impacting velocity,alumina droplet would rebound,stick,and breakup successively after impacting on the wall.With the increase of the diameter,the critical Weber number of alumina droplet between rebound and stick,stick and breakup decreases accordingly.The rebound-stick critical We number of 20μm,50μm and 100μm alumina droplet vertically impacting on the wall are 170,84 and 50 respectively,and the stick-breakup critical We number of impacting alumina droplet in diameters of 50μm and 100μm are 141and 129.The droplet breakup must have sufficient kinetic energy to overcome the energy consumed by viscous flow and surface tension.
作者
武冠杰
任全彬
付宇
刘元敏
胡春波
WU Guanjie;REN Quanbin;FU YuI;LIU Yuanmin;HU Chunbo(Science and Technology on Combustion,Internal Flow and Thermal-structure Laboratory,Northwestern Polytechnical University,Xi'an 710072,China;The Fourth Academy of CASC,Xi'an 710025,China)
出处
《固体火箭技术》
EI
CAS
CSCD
北大核心
2018年第6期677-683,共7页
Journal of Solid Rocket Technology
基金
National Natural Science Foundation of China(51576166)
关键词
氧化铝液滴
直接数值模拟
自适应网格方法
临界We数
alumina droplet
directly numerical simulations
self-adaptive grid method
critical We number
作者简介
WU Guanjie (1990-),male,Docter,specialty :Internal flow field in solid rocket motor.E-mail:wgj @mail.nwpu.edu.cn
