滑行段低温推进剂流动及换热特性对气枕压力的影响研究

Research on Influence of Cryogenic Propellant Flow Behavior and Heat Transfer Characteristics on Ullage Pressure in Coasting-Flight Phase

运载火箭在飞行过程中需要进行姿态调整以满足入轨要求,贮箱内推进剂在外界干扰力的作用下将发生晃动,由此引入了诸如气液接触面积、蒸发、冷凝过程及推进剂流动变化等不确定影响因素。实际飞行过程尤其是进入滑行段的初始推进剂晃动对贮箱内气枕压力及推进剂流动行为具有重要影响。在调研国内外运载火箭末级飞行过程中低温贮箱压力及推进剂流动特性的基础上,建立仿真模型,采用流体体积函数方法(VOF)分析滑行段推进剂流动特性变化对贮箱气枕压力的影响。

Attitude adjustment is needed during rockets’flight processes in order to meet the orbit requirement.The rocket’s attitude adjustment process will introduce propellant sloshing in the cryogenic tank,resulting in some uncertain effects such as variations of gas-liquid contact area,heat transfer process,evaporation/condensation process,and propellant flow behavior.In fact,initial propellant sloshing during the coasting-flight phase has notable influence on the ullage pressure and propellant flow behavior.In this paper,the influence of propellant flow behavior on the cryogenic tank pressure is studied via numerical simulation using VOF method,on the basis of literature research of cryogenic tank pressure and propellant flow behavior during the upper stage flight of launch vehicles.