摘要
火箭发动机水下工作时的流场特性与空中完全不同且对水下工作环境非常敏感。为了研究水下点火流场的非定常演化过程及点火水深、航行速度、汽化反应的影响规律,利用VOF多相流模型及SST k-ω湍流模型模拟了不同环境下的水下点火过程。研究结果表明:发动机水下工作过程大致分为3个阶段——初期发展阶段、振荡发展阶段与推力稳定阶段,稳定阶段尾流场又可划分为射流区、过渡区和掺混区,各阶段的划分受水深、航速等变量的影响;振荡是水下发动机工作最主要的特征,喷管出口燃气射流流动状态决定了流场与推力的基本特征;航速主要影响燃气泡形态演化规律,表现为轴向长度、颈缩程度增大;受汽化效应影响,流场中出现水蒸气的聚集现象,但由于作用时间短、水汽化量小,对流场与推力的影响相对较小。
The flow field characteristics of underwater ignition are completely different from ignition in the air and are very sensitive to the underwater working environment.In order to study the unsteady development process of underwater ignition and the influence law of various factors(such as depth,velocity,vaporization),a variety of underwater ignition conditions were studied by numerical simulation,utilizing the VOF multiphase model and SST k-ωturbulence model.The results show that,the process of underwater ignition can be divided into three stages:initial stage,oscillatory stage and stable stage.In the stable stage,the gas bubble can be divided into jet region,transition region and mixing region,and the division of different stages is affected by depth,velocity and so on.Oscillation is the most important characteristic in the working process.The working state of gas jet determines the characteristics of flow field and thrust.Velocity mainly affects the evolution law of gas bubble shape,which shows that the axial length and necking degree increases.Due to the influence of vaporization effect,the phenomenon of water vapor accumulation appears in the flow field,but the influence on the flow field and engine thrust are not significant due to the short interaction time and small amount of vapor.
作者
柳文杰
李冬
蔡强
李翔
张正
LIU Wenjie;LI Dong;CAI Qiang;LI Xiang;ZHANG Zheng(China Academy of Launch Vehicle Technology,Beijing 100076,China)
出处
《火箭推进》
CAS
2022年第5期76-83,共8页
Journal of Rocket Propulsion
基金
国家自然科学基金(11972377)。
