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Experimental Study on Heat Transfer and Flow Resistance in Improved Latticework Cooling Channels

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Journal of Thermal Science 2013年第3期22卷 250-256页

作者： hongwu deng Kai Wang Jianqin Zhu Wenyan Pan National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Jet Propulsion Beihang University Institute of Engineering Thermophysics Chinese Academy of Science

Characteristics of heat transfer and flow resistance of the latticework (vortex) cooling channel with ribs truncated at their two ends were theoretically and experimentally studied compared with regular and smooth channels of the same configuration. The results showed: the heat transfer efficiency of the latticework channel with two slots was better than those of regular and smooth channels of the same configuration, its flow resistance situation in the slotted channel becomes quite complex; The flow resistances of 2 mm- and 4 mm-slotted channels were obviously lower than that of the regular channel, but they are still much higher than that of the smooth channel; Compared with the regular channel, the total heat transfer efficiencies of the slotted channels were pretty improved, among them the 4-mm slotted channel has the biggest enhancement. From the experimental results, it is obvious that the latticework channel with proper slots has a great prospect in the design of the inner cooling channels of turbine blades.

关键词： latticework cooling turbine blade truncated ribs heat transfer flow resistance

Effect of Blockage Ratio on Heat Transfer and Pressure Drop in Rotating Ribbed Channels at High Rotation Numbers

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Journal of Thermal Science 2021年第3期30卷 902-913页

作者： deng hongwu LI Hua TAO Zhi QIU Lu ZHU Jianqin National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Energy and Power EngineeringBeihang UniversityBeijing 100191China

At high rotation numbers,the rotational effects on heat transfer and flow could be diverse among the channels with different blockage ***,most studies are conducted under low rotation number(less than 0.25)and selected blockage *** paper experimentally investigates the effect of rib blockage ratio(ranges from 0 to 0.3)on pressure loss and heat transfer in a rotating square channel under high rotation number(up to 0.81).The ribs staggered on leading and trailing walls were oriented 90°to the mainstream *** Reynolds number and the wall-to-fluid temperature ratio varied from 20000 to 40000 and 0.08 to 0.2,*** results showed that a larger blockage ratio resulted in a better heat transfer but a higher pressure *** optimum blockage ratio was 0.1 for the best thermal *** rotational effects were weakened in the passage with a higher blockage ratio,where the critical rotation number could not be ***,the heat transfer enhancement induced by rotation was more significant when the temperature ratio ***,the correlations were developed for the pressure drop and the convective heat transfer on the leading and trailing edges.

关键词： thermal performance rib blockage ratio high rotation number

Experimental research in rotating wedge-shaped cooling channel with multiple non-equant holes lateral inlet

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Chinese Journal of Aeronautics 2018年第3期31卷 457-469页

作者： Huimin ZHOU Haiwang LI Zhi TAO hongwu deng Meisong YANG Shuqing TIAN National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang University Collaborative Innovation Center of Advanced Aero-Engine Beihang University Research and Development Center AVIC Commercial Aircraft Engine Co. Ltd.

The heat transfer in a novel smooth wedge-shaped cooling channel with lateral ejection of turbine blade trailing edge is experimentally investigated in both non-rotating and rotating *** the conventional inlet at the bottom of the channel, an extra coolant injection from 8 lateral non-equant holes is introduced to improve the overall heat transfer. The total mass flow rate ratio（lateral mass flow rate/total mass flow rate） varies from 0 to 1.0. The major inlet Reynolds number and rotation number respectively vary from 10000 to 20000 and from 0 to 1.16. Experimental results show that the lateral inlet decreases local bulk temperature and increases local heat transfer at the middle and the top of the static channel. In rotating cases, the lateral inlet notably improves the heat transfer at the high-radius half channel and compensates the negative effects induced by the rotation. Both intensity and uniformity of heat transfer inside the channel are enhanced while flow resistance decreases with proper mass flow rate ratio of coolant from two inlets. The most satisfactory total mass flow rate ratio is around 2/3. This new structural style of cooling channel has huge potential and provides new direction of heat transfer of turbine blade trailing edge.

关键词： Heat transfer Lateral inlet Rotor blades trailing edge Rotating Wedge-shaped channel

Visualization Experiments of a Specific Fuel Flow Through Quartz-glass Tubes Under both Sub- and Supercritical Conditions

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Chinese Journal of Aeronautics 2012年第3期25卷 372-380页

作者： deng hongwu ZHANG Chunben XU Guoqiang TAO Zhi ZHU Kun WANG Yingjie National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Beihang University Beo'ing 100191 China Xi'an Aerospace Propulsion Institute Xi 'an 710100 China

The present work is a visualization study of a typical kerosene （RP-3） flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera. The experiments are accomplished at temperatures of 300-730 K under pressures from 0.107-5 MPa. Six distinctive two-phase flow patterns are observed in upward flow and the critical point of RP-3 is identified as critical pressure pc=2.33 MPa and critical temperature Tc=645.04 K and it is found that when the fluid pressure exceeds 2.33 MPa the flow can be considered as a single phase flow. The critical opalescence phenomenon of RP-3 is observed when the temperature is between 643.16 K and 648.61 K and the pressure is between 2.308 MPa and 2.366 MPa. The region filled by the critical opalescence in the upward flow is clearly larger than that in the downward flow due to the interaction between the buoyancy force and fluid inertia. Morecover, obvious layered flow phenomenon is observed in horizontal flow under supercritical pressures due to the differences of gravity and density.

关键词： visualization flow patterns critical opalescence supercritical layered fuel

Heat transfer characteristics in a rotating AR=4:1 channel with different channel orientations at high rotation numbers

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Propulsion and Power Research 2021年第2期10卷 130-142页

作者： Yang Li Jingwei Chen Wei Li hongwu deng Shulin Xue Hunan Key Laboratory of Turbomachinery on Small and Medium Aero-Engine AECC Hunan Aviation Powerplant Research InstituteZhuzhou412002China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Energy and Power EngineeringBeihang UniversityBeijing100191China

In order to reveal the effect of channel orientations on rotational heat transfer performance,this paper presents an experimental model of AR=4:1 smooth rectangular *** stationary and rotational heat transfer characteristics of the channel are studied in the range of Re=10,000-40,000 and Ro=0-1.23 under the channel orientation of 90°and 135°,which represent the basic one and realistic one,*** experimental results indicate that for the trailing wall,the 90°channel shows a typical large range enhancement of rotational heat transfer,while the rotational effect becomes negative in most areas at 135°*** the rotation number exceeds 0.7,the heat transfer of the trailing surface is greatly improved by rotational effect in 90°*** the channel was orientated at 135°,the leading surface heat transfer is more sensitive to rotation under the low rotation number(Ro<0.3),and 20%-30%worse than non-rotating *** averaged Nusselt ratios correlations under the channel orientation of 90°and 135°have been developed for further engineering applications.

关键词： Turbine blade cooling Rotational effect Heat transfer correlations High aspect ratio Channel orientation

Investigation of flow resistance characteristics of endothermic hydrocarbon fuel under supercritical pressures

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Propulsion and Power Research 2013年第2期2卷 119-130页

作者： Chunben Zhang Guoqiang Xu hongwu deng Kun Zhu National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Energy and Power EngineeringBeihang UniversityBeijing 100191China xi'an Aerospace Propulsion Institute Xi'an 710100China

The characteristics of flow resistance of a typical hydrocarbon fuel(RP-3)flowthrough adiabatic horizontal miniature tubes at supercritical pressures are experimentallyinvestigated for both laminar and turbulent *** experiments are conducted by using along tube measuring section and a short tube measuring section simultaneously in order toeliminate the effect of local pressure *** these experiments,the temperature of RP-3changes from(295 to 789)K and the reduced pressure(P/Pc,Pc=2.33 MPa)ranges from 1 to2.58,the mass flux is up to 1572.7 kg/(m^(2).s).Test results indicate that frictional pressuredrops for various supercritical pressures at the same mass flux can be considered as equalwith each other when the reduced temperature Tb/Tpc0.95,differenceappears and increases with the increase of Tb/***,the friction factor(f)of thesupercritical fluid for turbulent flow has a critical value at Tb/Tpc=1,the values of f at thispoint for all pressures and mass fluxes are equal with each ***,at the same massflux,there are two comresponding friction factors for the same Re,one is in the region of Tb/Tpc ***, classical conelations of frictionfactor is inapplicable when Tb/Tpc>0.95 at supercritical pressure and a new coelation hasbeen obtained based on the experimental data.

关键词： Supercritical Hydrocarbon fuel Flow resistance Friction factor Pressure drop

Buoyancy effect on heat transfer in rotating smooth square U-duct at high rotation number

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Propulsion and Power Research 2014年第3期3卷 107-120页

作者： Yang Li Guoqiang Xu hongwu deng Shuqing Tian National Key Laboratory of Science and Technology on Aero-Engine Aero-Themmodynamics&Collaborative Innovation Center of Advanced Aero-Engine Beihang UniversityBeijing 100191China R&D Center Dept of Discipline Engineering AVIC Commercial Aircrafit Engine CoLtdShanghai 201108China

The buoyancy effect on heat transfer in a rotating,two-pass,square channel is experimentally investigated in curent *** classical copper plate technique is performed to measure the regional averaged heat transfer *** order to perform a fundamental research,all turbulators are removed *** approaches of altering Buoyancy numbers are selected:varying rotation number from 0 to 2.08 at Reynolds number ranges of 10000 to 70000,and varying inlet density ratio from 0.07 to 0.16 at Reynolds number of *** thus,Buoyancy numbers range from 0 to 12.9 for both *** to the experimental results,the relationships between heat transfer and Buoyancy numbers are in accord with those obtained under different rotation *** both leading and trailing surface,a critical Buoyancy number exists for each X/D *** the critical point,the effect of Buoyancy number on heat transfer is limited;but after that,the Nusselt number ratios show different increase *** the same rotation number,higher wall temperature ratios with its corresponding higher Buoyancy numbers substantially enhance heat transfer on both *** the critical exceed-point that heat transfer from trailing surface higher than leading surface happens at the same Buoyancy number for different wall temperature ratios in the second ***,the stronger buoyancy effect promotes heat transfer enhancement at high rotation number condition.

关键词： Buoyancy effect Heat transfer Wall temperature ratio Rotating U-duct High rotation number

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高旋转数下带肋回转通道的换热特性

航空动力学报 2016年第2期31卷 360-368页

作者：张洪田淑青邓宏武李洋中国航空工业集团公司中航商用航空发动机有限责任公司设计研发中心上海201108 北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室北京100191

为匹配真实发动机转子叶片的工作条件,将实验回转通道气体压力提高到500kPa以上,使雷诺数和旋转数范围分别扩展到10 000～70 000和0～2.08.在此基础上通过实验方法研究了高旋转数下带45°倾角斜肋的方形截面回转通道的换热特性.结果表... 详细信息

为匹配真实发动机转子叶片的工作条件,将实验回转通道气体压力提高到500kPa以上,使雷诺数和旋转数范围分别扩展到10 000～70 000和0～2.08.在此基础上通过实验方法研究了高旋转数下带45°倾角斜肋的方形截面回转通道的换热特性.结果表明：回转通道的第1通道前缘面传热系数随旋转数的增大先减小,在达到临界旋转数后换热随旋转数增大而增强;低旋转数下,回转通道的第2通道前后缘面换热差异较小,随着旋转数的增大,前缘面换热始终强于后缘面,这种换热特性与光滑通道完全不同.

关键词：雷诺数高旋转数斜肋回转通道换热特性

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楔形扰流柱通道流动与传热特性

航空动力学报 2021年第1期36卷 34-41页

作者：李杰田淑青杨梅松邓宏武中国航空发动机集团有限公司商用航空发动机有限责任公司设计研发中心上海200241 北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室北京102206

针对处在高速旋转(哥氏力、离心力以及诱导产生的浮升力)状态下的涡轮转子叶片尾缘独特的几何结构(带扰流柱的楔形通道)和特殊的流动方式(径向进气侧向出流),采用实验的方法在实际工况参数范围内对其传热和流阻特性进行了详细研究:雷诺... 详细信息

针对处在高速旋转(哥氏力、离心力以及诱导产生的浮升力)状态下的涡轮转子叶片尾缘独特的几何结构(带扰流柱的楔形通道)和特殊的流动方式(径向进气侧向出流),采用实验的方法在实际工况参数范围内对其传热和流阻特性进行了详细研究:雷诺数和旋转数的变化范围为20 000~45 000、0~0.155。实验结果表明:扰流柱的存在使得径向区域底部的滞止区域变大,但这也让中部传热有明显的提升;流阻和综合传热系数的比光滑参数随着雷诺数的增加而下降;旋转对顶部传热有增强作用,底部传热减弱;总地来说旋转使得通道的平均传热减弱,流阻增加,综合传热系数下降。

关键词：旋转传热楔形通道扰流柱对流传热流阻特性