This study explores the design,analysis,and air pressure drop assessment of three anal-ogous air-fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number aero-engines.In high speed flight,the compressor bleed air used to cool high temper-ature turbine blades and other hot components is too hot.Hence,aviation kerosene is applied to precool the compressor bleed air by means of novel air-fuel heat exchangers.Three light and com-pact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured,with little difference existing in aspects of tube pitches and outer diameters among three heat exchangers.The fuel flows inside a series of parallel stainless serpentine tubes(outer diameter:2.2,1.8,1.4 mm with 0.2 mm thickness),while the air externally flows normal to tube bun-dles and countercurrent with fuel.Experimental studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet temperatures.Non-isothermal measurements have also been performed to research the effect of heat transfer on pressure drops.The experimental results show that inlet temperatures have signif-icant influence on pressure drops,and higher temperatures lead to higher pressure drops at the same mass flow rate.The hydraulic resistance coefficient decreases quickly with Reynolds number,and the descent rate slows down when Re＞6000 for all three heat exchangers.Additionally,the pres-sure drop on heat transfer states is less than that on isothermal states for the same average temper-atures.Moreover,the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches,and an asymmetric M-shaped velocity profile is generated in the cross-section of sector channels.

Yinlong LIU;Guoqiang XU;Yanchen FU;Jie WEN;Shaoshuai QI;Lulu LYU

Research Institute of Aero-engine,Beihang University,Beijing 100083,China;National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics,Beihang University,Beijing 100083,China;School of Energy and Power Engineering,Beihang University,Beijing 100083,China;Beihang Hangzhou Innovation Institute Yuhang,Hangzhou 310023,China;China Aerospace Aerodynamics Technology Research Institute,Beijing 100074,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;Shaoshuai QI;Lulu LYU-.Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for aero-engine cooling)[J].中国航空学报（英文版）,2022(12):32-46

Airside,ogous,precool,airside

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