Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection,the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertically downward circular miniature tube with an inner diameter of 1.86 mm at supercritical pressures and constant heat fluxes.A long and short tube method was used to accurately calculate the frictional pressure drop,and experimental conditions are supercritical pressures of 4 MPa,mass flow rates of 2-4 g/s(i.e.,mass fluxes of 736-1472 kg/(m2·s)),heat fluxes of 100-500 kW/m2,and inlet temperatures of 373-673 K.Results show that the sharp variations of thermophysical properties,especially density,have significant influences on frictional resistances.Generally,the frictional pressure drop and the friction factor increase with increasing inlet temper-atures,and this trend speeds up in the relatively high-temperature region.However,the friction fac-tor has a sudden decline when the fuel outlet temperature exceeds the pseudo-critical temperature.The frictional pressure drop and the friction factor basically remain unchanged with increasing heat flux when the inlet temperature is relatively low,but increase quickly when the inlet temperature is relatively high.Besides,a larger mass flux yields a higher pressure drop but does not necessarily yield a higher friction factor.Finally,an empirical friction factor correlation is proposed and shows better predictive performance than those of previous models.

Yinlong LIU;Guoqiang XU;Yanchen FU;Jie WEN;Geng GONG;Lulu LYU

Research Institute of Aero-engine,Beihang University,Beijing 100191,China;National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics,Beihang University,Beijing 100191,China;School of Energy and Power Engineering,Beihang University,Beijing 100191,China;Beihang Hangzhou Innovation Institute Yuhang,Hangzhou 310023,China;China Aerodynamics Research and Development Center,Mianyang 621000,China;AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China

中国航空学报（英文版）

[1]Yinlong LIU;Guoqiang XU;Yanchen FU;Jie WEN;Geng GONG;Lulu LYU-.Frictional resistance of supercritical pressure RP-3 flowing in a vertically downward tube at constant heat fluxes)[J].中国航空学报（英文版）,2022(09):117-128

Frictional,supercritical,RP,flowing,vertically,downward,tube,constant,heat,fluxes,Based,demands,compact,exchangers,micro,cooling,channels,applied,aviation,thermal,protection,characteristics,kerosene,were,experimentally,studied,circular,miniature,inner,diameter,pressures,long,short,method,was,used,accurately,calculate,frictional,drop,conditions,are,mass,rates,kW,inlet,temperatures,Results,that,sharp,variations,thermophysical,properties,especially,density,have,significant,influences,resistances,Generally,increase,increasing,this,trend,speeds,relatively,region,However,has,sudden,decline,when,fuel,outlet,exceeds,pseudo,basically,remain,unchanged,but,quickly,Besides,larger,yields,higher,does,not,necessarily,Finally,empirical,correlation,proposed,shows,better,predictive,performance,than,those,previous,models

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