PDF《超临界压力下航空煤油 RP-3 在水平细圆管内 对流换热特性实...》

? 超临界压力下航空煤油 RP-3 在水平细圆管内 对流换热特性实验研究 贾洲侠

1 ,付衍琛

2 ,孔凡金

1 ,刘宝瑞

1 ,吴振强

1 (1.

?北京强度环境研究所?可靠性与环境工程技术重点实验室,北京??100076;

2.?北京航空航天大学?能源与动力工程学院,北京??100191) 摘要:为探究超临界压力下碳氢燃料在水平管内的对流换热规律,文章针对超临界条件下航空煤油 RP-3 在水平细圆管内的对流换热,分析了热流密度、进口雷诺数及浮升力对对流换热的影响.研究表 明:沿流动方向,管内表面传热系数随热流密度的增大先减小后增大;

在低进口温度及低进口雷诺数情 况下,管内换热均出现先恶化后强化的现象,而随着进口温度和雷诺数的增加,此现象消失;

浮升力对 换热的影响随热流密度的增加而增加;

浮升力对下表面换热的加强使得入口效应的影响在下表面先于上 表面结束;

受浮升力影响,上下壁最大温差可达 50?K;

质量流速的增加会抑制浮升力对换热的影响;

准 则数 Grq/Grth 可以很好地反映浮升力的变化趋势.以上研究结果可为采用碳氢燃料作冷却介质的各类飞 行器主动热防护技术方案提供技术支撑. 关键词:主动热防护;

航空煤油;

水平流动;

对流换热;

超临界压力;

雷诺数;

浮升力 ???????中图分类号:V231.1 文献标志码:B 文章编号:1673-1379(2018)03-0233-08 DOI:?10.3969/j.issn.1673-1379.2018.03.006 Experimental study of convective heat transfer of aviation kerosene RP-3 in horizontal tube under supercritical pressures JIA?Zhouxia

1 ,?FU?Yanchen

2 ,?KONG?Fanjin

1 ,?LIU?Baorui

1 ,?WU?Zhenqiang

1 (1.?Science?and?Technology?on?Reliability?and?Environment?Engineering?Laboratory,?Beijing?Institute?of?Structure?and?Environment Engineering,?Beijing?100076,?China;

?2.?School?of?Energy?and?Power?Engineering,?Beihang?University,?Beijing?100191,?China) Abstract:? To ?better ?understand ?the ?convective ?heat ?transfer ?of ?the ?hydrocarbon ?fuel ?in ?horizontal ?tubes under?supercritical?pressures,?an?experimental?study?is?carried?out?for?the?convective?heat?transfer?of?the?aviation kerosene ?RP-3 ?in ?a ?horizontal ?miniature ?round ?tube. ?Under ?the ?working ?conditions ?of ?the ?air-kerosene ?heat exchanger,?the?aviation?kerosene?is?heated?up?to?the?supercritical?regime.?The?influences?of?the?heat?flux,?the?fluid inlet?temperature,?and?the?buoyancy?on?the?heat?transfer?of?the?RP-3?are?analyzed.?It?is?found?that?the?heat?transfer coefficients?decrease?with?the?increase?of?the?heat?flux,?and?the?buoyancy?causes?a?large?temperature?difference?of 50?K?between?the?top?and?the?bottom?surfaces?of?the?test?tube?under?high?heat?flux?conditions,?which?can?be predicted?by?the?non-dimensional?parameter?Grq/Grth.?The?effects?of?the?buoyancy?on?the?heat?transfer?can?be suppressed ?by ?increasing ?the ?mass ?flux. ?The ?results ?may ?provide ?a ?technological ?basis ?for ?the ?active ?thermal protection?of?the?flight?vehicles?to?be?cooled?by?hydrocarbon?fuels. Key words:? active ?thermal ?protection;

?aviation ?kerosene;

?horizontal ?flow;

?convective ?heat ?transfer;

supercritical?pressure;

?Reynolds?number;

?buoyancy ? 收稿日期:2017-11-03;

修回日期:2018-05-22 基金项目:国家自然科学基金项目(编号:11502023;

11502024;

11402028) ? 引用格式:贾洲侠, 付衍琛, 孔凡金, 等. 超临界压力下航空煤油 RP-3 在水平细圆管内对流换热特性实验研究[J]. 航天器环 境工程, 2018, 35(3): 233-240 JIA Z X, FU Y C, KONG F J, et al. Experimental study of convective heat transfer of aviation kerosene RP-3 in horizontal tube under supercritical pressures[J]. Spacecraft Environment Engineering, 2018, 35(3): 233-240 第?35?卷第?3?期航??天??器??环??境??工??程Vol.?35,?No.?3 2018?年?6?月SPACECRAFT?ENVIRONMENT?ENGINEERING