低温贮箱大热流下两相流态可视化试验  

Visualization Test Study on Two-Phase Flow Behaviors InsideCryogenic Tank Under High Heat Flux

作　　者：瞿淼 王磊[1] 孙培杰 严立 王其晓 厉彦忠[1] QU Miao;WANG Lei;SUN Peijie;YAN Li;WANG Qixiao;LI Yanzhong(Institute of Refrigeration and Cryogenic Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Shanghai Institute of Aerospace System Engineering,Shanghai 201109,China)

机构地区：[1]西安交通大学制冷与低温工程系,西安710049 [2]上海宇航系统工程研究所,上海201109

出　　处：《西安交通大学学报》2023年第9期62-70,共9页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51976151)。

摘　　要：为研究大热流下低温推进剂贮箱箱内流体温度分层与沸腾气泡特征,以液氮为试验流体,搭建了低温贮箱变热流可视化相态观测平台,通过改变吹风温度与吹风速度,实现了1~16 kW·m-2热流边界调节,与火箭升空过程中承受气动热流冲击基本一致。试验结果表明:低温贮箱壁面受大热流作用,并不一定产生沸腾气泡;当壁面热流密度小于2 kW·m-2,直至液体主体过冷度降至1 K时,近壁区才有气泡产生;壁面热流密度达到16 kW·m-2以上后,即使液体主体区过冷度超过10 K,近壁区也可能产生沸腾气泡;当液体主体存在较大过冷度时,火箭升空过程的气动加热仅会造成近壁区出现气泡;在对低温贮箱增压时,提高增压气体注入速率,加快增压进程有利于延缓近壁区液体温升与沸腾发生。此外,建立了一种预测沸腾气泡发生边界的经验模型,可对裸壁贮箱在大热流下是否发生推进剂沸腾提供初步预测,从而为火箭贮箱绝热方案设计提供支撑。In order to investigate the thermal stratification and boiling bubble features in the cryogenic propellant tank under great heat flux conditions,a visual platform was built,using liquid nitrogen as the test fluid.By adjusting the blowing temperature and speed,a heat flux boundary range of 1—16 kW·m-2 was achieved,which was basically consistent with the aerodynamic heat flow impact during rocket launching.The results show that a high heat flux at the tank wall surface does not necessarily bring about boiling bubbles;when the heat flux density is less than 2 kW·m-2,bubbles are generated in the near-wall region until the subcooling degree of the bulk liquid decreases to 1 K;comparatively,when the heat flux density exceeds 16 kW·m-2,a high subcooling degree of 10 K of the bulk liquid could yield boiling bubbles.When there is a large degree of subcooling in the bulk liquid,the aerodynamic heating during rocket launch only causes bubbles in the near-wall region.Increasing the pressurized gas injection rate during the pressurization period of the cryogenic tank could postpone the liquid temperature rise as well as boiling occurrence in the near-wall region.In addition,an empirical model was established to describe the boundary of boiling bubbles,which can offer preliminary predictions on whether propellant boiling occurs in bare-wall storage tanks under high heat flux,thus providing support for the design of the insulation scheme for the rocket tank.

关 键 词：低温推进剂 沸腾气泡 两相流态 可视化试验 

分 类 号：V511.6[航空宇航科学与技术—航空宇航推进理论与工程]