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Journal of Thermal Science 2024年第5期33卷 1883-1896页

作者： CAI Wenzhe WU Jing HU Yingqi YANG Zhiqiang XUE Xin LIN Yuzhen National Key Laboratory of Science and technology on Aero-engine Aero-thermodynamics Research Institute of Aero-EngineBeihang UniversityBeijing 100191China Beijing Institute of Power machinery Beijing 100074China School of Energy and Power engineering Beihang UniversityBeijing 100191China

Experimental analysis was conducted to study the impact of fuel-air mixing and dilution jet on the temperature distribution in a small gas turbine combustor using various optical diagnostic *** strength and velocity of the swirler at the venturi exit were adjusted to modify the fuel-air mixture,which is presumed to dominate the heat release of the main combustion ***,the dilution hole configuration,including the number and size of the holes,was varied to investigate the dilution effect on outlet temperature *** optical diagnostic techniques,such as particle image velocimetry,planar Mie scattering,and OH~*chemiluminescence,were used to measure the flow field,fuel spray distribution,and flame structure,respectively.A reduction in swirling strength led to a decrease in the average flow rate in the throat,which improved the structure and symmetry of the axial vortex system in the sleeve,enhanced the mixing of fuel and gas in the dome swirling air,and ultimately,improved the temperature uniformity of the heat release *** to larger and sparse dilution jets,smaller and dense dilution jets tended to generate hot spots shifted towards the radial middle area.

关键词： small gas turbine combustor fuel-air mixing outlet temperature distribution dilution jet laser diagnostics

Breaking the geometry-performance tradeoff in compressor deviation modeling:Nested principal component analysis

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Chinese Journal of Aeronautics 2024年第9期37卷 131-149页

作者： Mingzhi LI Xianjun YU Dejun MENG Guangfeng AN Baojie LIU Research Institute of Aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&technology on Aero-engine Aero-Thermodynamics Beihang UniversityBeijing 100191China AECC Shenyang engine Research Institute Shenyang 110015China

Uncertainties in the aerodynamic performance of compressors,introduced by manufac-turing variations,have received more and more attentions in recent *** deviation model plays a crucial role in evaluating this uncertainty and facilitating robust ***,current deviation models with a few variables cannot simultaneously achieve a precise geometric approxi-mation of deviation and provide an accurate assessment of performance *** paper introduces a novel deviation modeling method named Nested Principal Component Analysis(NPCA)to break this *** this method,both geometry-based and performance-based modes are utilized to describe manufacturing *** considering aerodynamic sensitivity,surface deformations that significantly impact aerodynamic performance can be extracted for deviation *** demonstrate the superiority of this newly proposed method,ninety-eight newly man-ufactured compressor rotor blades were measured using a coordinate measurement machine,and both NPCA and Principal Component Analysis(PCA)were employed to model the real manufac-turing *** results indicate that,in comparison to the PCA method,the NPCA method achieves an equivalent level of accuracy in geometric reconstruction and evaluation of mean ***,the same level of accuracy can be obtained with eight NPCA modes and fifty PCA modes when assessing the scatter in aerodynamic ***,the working mecha-nism of the NPCA method for accurate uncertainty quantification was further investigated.

关键词： Manufacturing variation Uncertainty quantification Dimension reduction Aerodynamics Flow mechanism

Development of a deviation package method for low-cost robust optimization in compressor blade design

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Chinese Journal of Aeronautics 2024年第4期37卷 166-180页

Manufacture variations can greatly increase the performance variability of compressor blades. Current robust design optimization methods have a critical role in reducing the adverse impact of the variations, but can be affected by errors if the assumptions of the deviation models and distribution parameters are inaccurate. A new approach for robust design optimization without the employment of the deviation models is proposed. The deviation package method and the interval estimation method are exploited in this new approach. Simultaneously, a stratified strategy is used to reduce the computational cost and assure the optimization accuracy. The test case employed for this study is a typical transonic compressor blade profile, which resembles most of the manufacture features of modern compressor blades. A set of 96 newly manufactured blades was measured using a coordinate measurement machine to obtain the manufacture variations and produce a deviation package. The optimization results show that the scatter of the aerodynamic performance for the optimal robust design is 20% less than the baseline value. By comparing the optimization results obtained from the deviation package method with those obtained from widely-used methods employing the deviation model, the efficiency and accuracy of the deviation package method are demonstrated. Finally, the physical mechanisms that control the robustness of different designs were further investigated, and some statistical laws of robust design were extracted.

关键词： Manufacture variations Robust design optimization Compressor leading edge Aerodynamics Physical mechanism

Insights into thermodynamic performance of a hypersonic precooled air-breathing engine with a complicated multi-branch closed cycle

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Chinese Journal of Aeronautics 2024年第8期37卷 106-123页

作者： Yifan WANG Zhengping ZOU Pengcheng DU Lichao YAO Huoxing LIU Yusen XU Research Institute of Aero-engine Beihang UniversityBeijing 102206China National Key Laboratory of Science and technology on Aero-engine and Aero-Thermodynamics Beihang UniversityBeijing 102206China

An advanced precooled airbreathing engine with a closed Brayton cycle is a promising solution for high-speed propulsion,of which the Synergetic Air Breathing Rocket engine(SABRE)is a representative *** performance of the latest SABRE-4 cycle was analyzed in this ***,a relatively complete engine performance model that considers the characteristics of turbomachinery and heat exchangers was ***,Sobol’global sensitivity analysis of key performance parameters was carried out to identify the most influential design *** specific impulses under different target specific thrusts were obtained by particle swarm optimization,of which the thermodynamic parameters corresponding to a specific thrust of 1.12 kN·s·kg^(-1)and a specific impulse of 3163 s were chosen as the design *** different control laws were analyzed in contrast,and the charge control method had the strongest ability of thrust regulation as well as maintaining a favorable specific impulse ***,working characteristics under the charge control and over a typical flight envelope were calculated,in which the average value of the maximum specific impulse was as high as 5315 *** study would help to deepen the understanding of SABRE-4 thermodynamic characteristics and other precooled airbreathing engine cycles with similar layouts.

关键词： Hypersonic Precooled airbreathing engine Thermodynamic cycle Control law Working characteristics

Analysis on the turning point of dynamic in-plane compressive strength for a plain weave composite

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Defence technology（防务技术） 2024年第2期32卷 485-495页

作者： Xiaoyu Wang Zhixing Li Licheng Guo Zhenxin Wang Jiuzhou Zhao department of Astronautic Science and Mechanics Harbin Institute of TechnologyHarbin150001China AECC Commercial Aircraft engine Co LTDShanghai201108China

Experimental investigations on dynamic in-plane compressive behavior of a plain weave composite were performed using the split Hopkinson pressure bar. A quantitative criterion for calculating the constant strain rate of composites was established. Then the upper limit of strain rate, restricted by stress equilibrium and constant loading rate, was rationally estimated and confirmed by tests. Within the achievable range of 0.001/s-895/s, it was found that the strength increased first and subsequently decreased as the strain rate increased. This feature was also reflected by the turning point(579/s) of the bilinear model for strength prediction. The transition in failure mechanism, from local opening damage to completely splitting destruction, was mainly responsible for such strain rate effects. And three major failure modes were summarized under microscopic observations: fiber fracture, inter-fiber fracture, and interface delamination. Finally, by introducing a nonlinear damage variable, a simplified ZWT model was developed to characterize the dynamic mechanical response. Excellent agreement was shown between the experimental and simulated results.

关键词： Plain weave composite Dynamic strength Quantitative criterion Turning point Failure mechanism

Geometric error measuring,modeling,and compensation for CNC machine tools:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao ZHANG Feng JIANG Ming LUO Baohai WU Dinghua ZHANG Kai TANG engineering Research Center of Advanced Manufacturing technology for Aero engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China department of Mechanical and Aerospace engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

Experimental Investigation on Heat Transfer and Combustion of a Stirling engine Combustor Fueled by Reformed Gas and Diesel Fuel

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Journal of Thermal Science 2024年第5期33卷 1907-1919页

作者： LAN Jian ZHAO Yanchun LIN Guangtao LI Yelin REN Zhe LYU Tian SHEN Mengmeng GU Genxiang HAN Dong Key Laboratory for Power machinery and engineering Ministry of EducationShanghai Jiao Tong UniversityShanghai200240China Shanghai Marine Diesel engine Research Institute Shanghai 201108China

Thermochemical recuperation heat recovery is an advanced waste heat utilization technology that can effectively recover exhaust waste heat from oxy-fuel Stirling *** novel combustor of a Stirling engine with thermochemical recuperation heat recovery system is expected to utilize both reformed gas and diesel fuels as sources of *** this research,the effects of various factors,including the H_(2)O addition,fuel distribution ratio(FDR),excess oxygen coefficient,and cyclone structure on the temperature distribution in the combustor,combustion emissions,and external combustion system efficiency of the Stirling engine were experimentally *** the increase of steam-to-carbon ratio(S/C),the temperature difference between the upper and lower heating tubes reduces and the circumferential temperature fluctuation decreases,and the combustion of diesel and reformed gas remains close to complete *** S/C=2,the external combustion efficiency is 80.6%,indicating a 1.6%decrease compared to conventional *** the increase of FDR,the temperature uniformity of the heater tube is improved,and the CO and HC emissions ***,the impact of the FDR on the maximum temperature difference and temperature fluctuation across the heater is *** the FDR rises from 21%to 38%,the external combustion efficiency increases from 87.4%to92.3%.The excess oxygen coefficient plays a secondary role in influencing temperature uniformity and temperature difference,and the reformed gas and diesel fuel can be burned efficiently at a low excess oxygen coefficient of *** an increase in the cyclone angle,the heater tube temperature increases,while the maximum temperature difference at the lower part decreases,and the temperature fluctuation ***,the CO and HC emissions increase,and the external combustion efficiency experiences a decrease.A cyclone angle of 30°is found to be an appropriate value for achieving optimal

关键词： Stirling engine fuel reforming synthetic gas oxy-combustion external combustion efficiency

Lubrication condition monitoring of journal bearings in diesel engine based on thermoelectricity

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Friction 2024年第11期12卷 2532-2547页

作者： Yuhao LV Hao LIU Zhigang CHEN Weijie CHANG Hui ZHANG Hulin LI Shanghai Jiao Tong University Shanghai 200240China National Key Laboratory of Marine engine Science and technology Shanghai 201108China Shanghai Marine Diesel engine Research Institute Shanghai 201108China Hunan Aviation Powerplant Research Institute Aero Engine Corporation of ChinaHunan 412002China

There is still a lack of effective lubrication condition monitoring methods in the field of diesel *** paper proposes a novel thermoelectric approach to divide the lubrication state of ***,the generation mechanism of thermoelectric potential on bearings is ***,both experimental and simulation studies are done,and a strong correlation between lubrication and thermoelectric potential is *** film thickness and temperature are further confirmed as significant factors influencing thermoelectric ***,the thermoelectric potential increases with ***,a small film thickness ratio(when the film thickness ratio is less than 4)will suppress the thermoelectric *** typical lubrication states of bearings are distinguished through thermoelectric potential and supported by the Stribeck curve ***,the significant influence of lubrication on the bearing is confirmed through the analysis of surface morphology and composition.

关键词： journal bearing lubrication state,thermoelectric potential condition monitoring

Experimental and numerical investigation of two blended blade and endwall configurations

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Chinese Journal of Aeronautics 2024年第9期37卷 150-163页

作者： Tongtong MENG Xin LI Ling ZHOU Lucheng JI Institute for Aero engine Tsinghua UniversityBeijing 100084China Schoolof Aerospace engineering Bejing Institute of TechnologyBeijing 0081China

The Blended Blade and Endwall(BBEW)technique has proven to be effective in control-ling the intersection of boundary layer in corner region of the compressor *** this study,the experiment and analysis of two different BBEW designs are ***,based on a linear cas-cade with 0.7 Mach number inflow,two different configurations,BBEW 1 and BBEW 2,are well ***,according to the experimental result,control effects of these two BBEW configu-rations are validated and compared subsequently under various working *** results demonstrate a reduction in total pressure loss of 12.8%and 29%at the design point for BBEW 1 and BBEW 2,***,the BBEW technique proves effective in suppressing the development of the boundary layer and preventing corner *** by detailed numerical analysis,improvements around the corner region,especially for the boundary layer,are extracted to show the mechanisms and distinctions between the two *** results indicate that BBEW 1 significantly restrains the development of boundary layer before separation occurs,while BBEW 2 directly controls the strength and scale of the corner separation.

关键词： Aerodynamic Computational fluid dynamic Experiment Corner separation Blended Blade and Endwall(BBEW)

Experimental investigation of junction growth of rough contacts using X-ray computed tomography

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Friction 2024年第11期12卷 2519-2531页

作者： Runliang WANG Jianhua LIU Bo LIU Duo JIA Xiaoyu DING School of Mechanical engineering Beijing Institute of TechnologyBeijing 100081China AECC Shenyang engine Research Institution Shenyang 110000China

The real contact area(RCA)of randomly rough contacts has received a great deal of attention because it correlates strongly with friction,lubrication,sealing,and *** have revealed that the RCA associated with deterministic normal squeezing loads increases when tangential loads are also applied,in a phenomenon called junction ***,experimental investigations of the junction growth of randomly rough contacts are ***,we used X-ray computed tomography(CT)to measure junction growth when two aluminum alloy surfaces were in contact.A high-resolution experimental setup was used to apply loads and observe contact behaviors at a resolution of 4μ*** RCA and average contact gaps were computed using a three-dimensional(3D)geometric model constructed from gray CT images using the Otsu thresholding *** results showed that the RCA increased as the normal load *** RCA increased by 22.67%after a tangential load was applied(junction growth),and the average gap decreased by 14.01%after a tangential load was ***,X-ray CT accurately measured the junction growth as a novel quantitative method.

关键词： three-dimensional(3D)contact analyses real contact area(RCA),junction growth X-ray computed tomography(CT) assembly interfaces