微重力下低温液氧贮箱热分层研究  

Research on thermal stratification of cryogenic liquid oxygen tank in microgravity

作　　者：刘展[1] 孙培杰 李鹏 厉彦忠[1] 晋永华[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049 [2]上海宇航系统工程研究所,上海201108

出　　处：《低温工程》2016年第1期25-31,53,共8页Cryogenics

基　　金：国家自然科学基金(51376142);航天低温推进剂技术国家重点实验室开放课题(SKLTSCP1407);上海航天核攀项目(ZY2015-015)项目资助

摘　　要：为研究微重力下,在轨运行低温液氧箱体内部流体温度场分布,建立了相关数值模型,考虑了气液相变以及各空间辐射热流的影响。计算结果表明:当g为0 g_0时,表面张力驱使液相包裹气枕,并将球形气枕挤出壁面。由于箱内没有自然对流,箱体壁面流体会出现局部过热。当g增加到10^(-6)g_0时,表面张力作用仍较为明显。箱体内部物理场分布与0 g_0工况大致相同。当g增加到10^(-5)g_0时,液相已不能完全包裹气相,气相区一直与箱体顶部接触。当g增加到10^(-4)g_0时,此时箱体内部自然对流已十分明显,气相区大致呈带状,并与顶部壁面有较大的接触面积。短时间内,自然对流可及时将外部漏热带入箱体内部。另外,箱体压力随时间增长呈先降低后逐渐升高的趋势。重力越小,箱体压力也越小。最后通过对比还发现,初始边界条件设置对箱体内部物理场有较大的影响。One numerical calculation model is built to investigate the temperature distribution of on-orbit cryogenic oxygen tank in microgravity,with phase change and different space radiations considered. The results show that when gravity sets as 0 g_0,the liquid would encircle the ullage under the influence of surface tension,and the spherical ullage breaks away from tank wall and moves toward the tank bottom. Local overheating appears in fluid close to tank wall due to the lack of free convection in tank. While gravity increases to 10^（- 6）g_0,the effect of surface tension is still obvious and the tank physical distribution is almost the same as that of 0 g_0. When gravity increases to 10^（- 5）g_0,the liquid could not encircle the ullage fully and the ullage always touches the top of the tank. While gravity increases to 10^（- 4）g_0,free convection becomes more and more evident. The ullage looks like a ribbon and touches a large area of tank top. The external heat leakage could enter the tank in short time by fluid free convection. Moreover,tank pressure reduces firstly and then increases gradually. A smaller gravity causes to a smaller tank pressure. Finally,it is found that initial boundary condition setup has a large influence on tank physical distribution.

关 键 词：微重力 低温液氧箱体 热分层 空间辐射 

分 类 号：TB657[一般工业技术—制冷工程]