变重力下低温液氮界面流动及温度分布  

Research on Interfacial Flow and Thermal Stratification of Cryogenic Liquid Nitrogen in Variable Gravity

作　　者：章敏 刘秋生[1,2] 陶跃群 何乃峰 ZHANG Min;LIU Qiusheng;TAO Yuequn;HE Naifeng(Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院力学研究所微重力重点实验室,北京100190 [2]中国科学院大学工程科学学院,北京100049

出　　处：《空间科学学报》2024年第5期846-862,共17页Chinese Journal of Space Science

基　　金：国家自然科学基金资助项目(11532015);中国载人空间站空间蒸发相变与传热强化实验研究项目(TGMTYY14019-1);变重力推进剂流体管理研究项目(YYWT0601EXP1901);中–欧载人航天应用合作项目(Y935011041);中国科学院国际伙伴计划对外重点项目(115111KYSB20200008)共同资助。

摘　　要：为了研究残余重力加速度g对液氮贮箱自加压期间贮箱内流体的流动、相分布、温度分布以及压强分布的影响,针对液氮贮箱,采用流体体积(Volume-of-Fluid,VOF)方法数值模拟了不同g条件下液氮贮箱的自加压过程.研究结果表明:在大g情况下,贮箱内压强沿g的方向逐渐增大,贮箱内气枕的温度随贮箱壁面的持续漏热而不断升高,且靠近壁面区域气体的温度最高,靠近液体区域气体的温度最低;随着g的减小,贮箱内的液体更容易沿贮箱壁面爬升,贮箱内流体温度差异性逐渐减小;在小g情况下,贮箱内流体流动稳定后会将气枕包裹于贮箱中部,形成球形气泡,贮箱内流体温度的差异性随时间先逐渐增大然后逐渐减小.在零重力环境下,贮箱壁面漏热(q_(w)=0.5 W·m^(–2))存在与否对贮箱内流体运动和相分布的影响均不显著,并且在起始一段时间间隔△t_(f)(0≤△t_(f)≤40 s)内,除贮箱壁面附近之外,q_(w)存在与否对贮箱内流体温度分布的影响也不显著.In order to study the effects of residual gravitational acceleration g on the flow,phase distribution,temperature distribution,and pressure distribution of liquid nitrogen tank during self-pressurization,the self-pressurization process of liquid nitrogen tank under different g was numerically simulated by the Volume-of-Fluid(VOF)method.The results show that under the condition of large g,the fluid pressure in the tank increases gradually along the direction of residual gravity,and the temperature of the ullage in the tank increases with the continuous heat leakage of the tank wall,and the gas tempera-ture near the wall is the highest,and the gas temperature near the liquid is the lowest,while the temper-ature in the liquid bulk zone of the tank changes little with time.With the decrease of g,the liquid in the tank is more likely to climb along the wall of the tank with better infiltration,and the temperature difference of the fluid in the tank is gradually reduced.In the case of small g,after the fluid flow in the tank is stable,the ullage will be wrapped in the middle of the tank,forming a spherical bubble.The dif-ference of the fluid temperature in the tank gradually increases and then decreases with time.In zero gravity environment,the presence or absence of heat leakage(q_(w)=0.5 W·m^(-2))on the tank wall has no significant influence on the fluid movement and phase distribution in the tank,and within the initial time interva△t_(f)(0≤△t_(f)≤40 s),the influence of the presence or absence of q_(w)on the temperature distribution of the fluid in the tank also is not significant except near the wall of the tank.Numerical simulation results are expected to provide references to further study the on-orbit pressure control technique of cryogenic liquid tanks and space cryogenic fluid management.

关 键 词：液氮 界面变形 温度分层 贮箱壁面漏热 数值仿真 

分 类 号：V511[航空宇航科学与技术—航空宇航推进理论与工程]