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An experimental study of noise generated by tandem blades

Chinese Journal of Aeronautics 2025年第2期38卷 143-160页

作者： Xiaolong TANG Fan TONG Chao WANG Jue DING Guangming LI Xiaoquan YANG Shanghai Institute of Applied Mathematics and Mechanics Shanghai Frontier Science Center of MechanoinformaticsShanghai Key Laboratory of Mechanics in Energy EngineeringSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Key Laboratory of Aerodynamic Noise Control China Aerodynamics Research and Development CenterMianyang 621000China Equipment Design and Testing Technology Research Institute China Aerodynamics Research and Development CenterMianyang 621000China

To facilitate the low-noise design of tandem lift bodies as applied in aeroengines and aircraft,the acoustic features of tandem blades are investigated by wind-tunnel *** is further specialized for the rotating blades applied in contra-rotating open rotors under the concept of frozen-rotor.A 70-channel phased microphone array and nine high-precision free-field microphones are *** beamforming method,enhanced by a source filtering technique,is employed to locate noise sources,providing insights into the source patterns of blade-blade interaction noise concerning flow speed,blade spacing,and aft blade *** results show the following:(A)Sources of tandem-blade noise exist in the form of concentrated source clusters,resulting in two major clusters:the mid-span interaction noise and the tip-induced noise.(B)These source clusters tend to separate as flow speed or blade spacing increases.(C)By increasing blade spacing,the band-pass filtered overall sound pressure level is reduced by 2.9 dB.(D)A two-phase noise suppression pattern is observed with blade clipping,resulting in a total reduction of 3.0 dB for the interaction noise through the removal of tip-induced noise sources and the replacement of mid-span noise *** on these findings,suggestions concerning blade spacing and clipping are discussed.

关键词： Tandem blades Contra-rotating open rotor Noise Beamforming Blade spacing and clipping Wind tunnel test

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Modulating Electromagnetic Genes Through Bi-Phase High-Entropy Engineering Toward Temperature-Stable Ultra-Broadband Megahertz Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第7期17卷 262-277页

作者： Xiaoji Liu Yuping Duan Nan Wu Guangming Li Yuan Guo Jiangyong Liu Ning Zhu Qiang Wang Lin Wang Zichen Xu Hao Wei Guojun Wang Zhijia Zhang Songsong Zhang Wenjun Zhou Teng Ma Tongmin Wang Qingdao Innovation and Development Base of Harbin Engineering University Harbin Engineering University Key Laboratory of Solidification Control and Digital Preparation Technology School of Materials Science and EngineeringDalian University of Technology National Key Laboratory of Electromagnetic Effect and Security On Marine Equipment China Ship Development and Design Center Wuhan Second Ship Design and Research Institute

Magnetic absorbers with high permeability have significant advantages in lowfrequency and broadband electromagnetic wave （EMW） ***,the insufficient magnetic loss and inherent high conductivity of existing magnetic absorbers limit the further expansion of EMW absorption ***,the spinel （FeCoNiCrCu）3O4high-entropy oxides （HEO） are successfully constructed on the surface of FeCoNiCr0.4Cu0.2high-entropy alloys （HEA） through low-temperature oxygen bath *** the one hand,HEO and HEA have different magnetocrystalline anisotropies,which is conducive to achieving continuous natural resonance to improve magnetic *** the other hand,HEO with low conductivity can serve as an impedance matching layer,achieving magneto-electric *** the thickness is 5 mm,the minimum reflection loss （RL） value and absorption bandwidth （RL<-5 d B） of bi-phase high-entropy composites （BPHEC） can reach-12.8 d B and 633 MHz,*** RCS reduction value of multilayer sample with impedance gradient characteristic can reach 18.34 d B *** addition,the BPHEC also exhibits temperaturestable EMW absorption performance,high Curie temperature,and oxidation *** absorption bandwidth maintains between 593 and 691 MHz from-50 to 150℃.This work offers a new and tunable strategy toward modulating the electromagnetic genes for temperature-stable ultra-broadband megahertz EMW absorption.

关键词： Bi-phase high-entropy composites Continuous natural resonance Electromagnetic genes Electromagnetic wave absorption Ultra-broadband

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Effect of Incoming Vortex on Secondary Flows in Turbine Cascades with Planar and Non-Axisymmetric Endwall

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Journal of Thermal science 2024年第1期33卷 138-157页

作者： CAO Zhiyuan WANG Chuxuan SONG Zhigao GAO Xi ZHAO Wei LIU Bo School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical UniversityXi'an 710072China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100080China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100080China

Non-Axisymmetric Endwall Profiling(NAEP) is commonly utilized in turbines to eliminate secondary ***,most of the NAEP methods consider a single-blade row environment without incorporating the effect of the stage *** paper aims to investigate the influence mechanism of the incoming vortex on the endwall secondary flow structures of NAEP in a highly loaded turbine *** model the incoming vortex in a stage environment,this study considers a half-delta wing as the vortex generator at the upstream of the turbine *** NAEP is then carried out for a highly loaded turbine cascade with an in-house numerical optimization design platform subject to no incoming *** simulation is also carried out under the influence of the incoming vortex for the turbine cascades with both planar and non-axisymmetric *** paper furthers investigated the pitchwise effect of the incoming vortex on the near endwall secondary *** results indicate that the NAEP effectively improves the endwall secondary flow of the turbine cascade,where the total pressure loss coefficient and the secondary kinetic energy(SKE) are reduced by 7.3%,and 45.7%,*** is further seen that with the incoming vortex,the NAEP achieves a considerable control effect on the endwall secondary flow of the turbine *** incoming vortex,the NAEP can still achieve considerable control effect on the endwall secondary flow of the turbine cascade;the averaged reductions of loss coefficient and SKE are 7.8% and 14.2%,*** some pitchwise locations,incoming vortex can suppress the convection of cross-passage flow toward the suction corner greatly and reduce the loss coefficient of the baseline *** incoming vortex at 4/7 pitch impinged right at the blade leading edge,leading to the generation of low-momentum fluid,which increased the size and the strength of the horseshoe *** all the pitchwise locations,NAEP can suppress the seco

关键词： non-axisymmetric endwall secondary flow incoming vortex passage vortex stage environment

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Strengthening in gradient TiAl alloys

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Journal of Materials science & technology 2023年第35期166卷 98-105页

作者： P.Li Y.Chen X.Liu X.H.Wang F.R.Chen Z.X.Qi G.Zheng H.G.Xiang G.Chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing210094China

Gradient structure is emerging as an effective strategy to fabricate metals with remarkable mechanical performance,but have not been verified in intermetallic compounds for high-temperature *** experiments and atomic simulations,we show that a typical intermetallic TiAl alloy with gra-dient structure has a significant strengthening effect both at room temperature and high *** room-temperature compressive strength of TiAl alloys with gradient grain obtained by additive man-ufacturing is 2.57 GPa,which is∼2.7 times as strong as that with equiaxed *** strengthening effect is attributed to more sessile dislocations in gradient structure caused by the intersections of mul-tiple slip systems in gradient *** importantly,the strengthening effect is still effective at high temperatures and the compressive strength is 1.28 GPa at 750°*** simulation results show that this strengthening effect is due to the increased Hirth dislocation at high *** study expands the applications of TiAl alloys for load-bearing structures and provides a new strategy for improving the strength of intermetallic compounds at both room temperature and high temperatures.

关键词： TiAl alloys Strengthening Gradient grain Additive manufacturing Molecular dynamics

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Mechanical behavior of TiAl alloys

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science China(Technological sciences) 2023年第9期66卷 2457-2480页

作者： XIANG HengGao CHEN Yang QI ZhiXiang ZHENG Gong CHEN FengRui CAO YueDe LIU Xu ZHOU Bing CHEN Guang National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

Intermetallic TiAl alloys attract much attention in advanced engineering fields due to their low density(3.9–4.2 g/cm3) and excellent high-temperature properties. After more than half a century of research and development, TiAl alloys have found applications in aerospace, automotive, and related industries. However, as a kind of semi-brittle materials, intermetallic TiAl alloys exhibit different mechanical behavior from metallic and ceramic materials. Thus, it is necessary to systematically understand their mechanical behavior to ensure further developments and safe engineering applications. In this paper, the principal mechanical behavior of Ti Al alloys was reviewed comprehensively, including tension, creep, fatigue, and strengthening mechanisms. The mechanical performance and the corresponding deformation mechanisms are summarized and discussed in detail. The future directions of mechanical research on TiAl alloys are also overviewed to expedite their extensive utilization in engineering fields.

关键词： TiAl tension creep fatigue strengthening mechanisms

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Strengthening and toughening bulk Ni_(2)CoFeV_(0.5) medium-entropy alloy via thermo-mechanical treatment

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Journal of Materials science & technology 2023年第20期151卷 19-29页

作者： Lei Gu Rui Hou Yi Liu Guang Chen Jihua Liu Gong Zheng Ruisheng Zhang Yonghao Zhao National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

Single-phase face-centered cubic(fcc)medium-and high-entropy alloys(MEAs/HEAs)have high ductility but low yield *** this work,the microstructures of single-phase fcc Ni_(2)CoFeV_(0.5) MEAs were tailored by cold-rolling and subsequent annealing and typical heterogeneous lamella(HL)structures composed of recrystallized micro-grain lamellae(with an averaged grain size of∼4μm)and nonrecrystallized nano-/ultrafine-grain lamellae were *** tests revealed that most HL samples exhibited excellent strength and ductility *** HL sample with∼23 vol%recrystallized grains annealed at 590℃ for 1 h had a high yield strength of 1120 MPa and a good fracture elongation of 12.3%,which increased by 5%and 46%,respectively compared with those of as-rolled ***-induced yield strength increase is attributed to high-density annealing twin boundaries(TBs)in the recrystallized grains,the annihilation of mobile dislocations inside the non-recrystallized grains,and extra heterodeformation-induced strengthening produced by the HL ***-Petch relationship of Ni_(2)CoFeV_(0.5) MEA can be reasonably described by counting both TBs and grain boundaries,with lattice friction stress of 87.3 MPa and coefficient of 722.8 MPaμm1/*** work provides optional and controllable solutions for preparing MEAs/HEAs with excellent mechanical properties by low-cost and high-efficiency thermomechanical treatments.

关键词： Medium-entropy alloys Microstructures Strength and ductility Heterogeneous lamella structure Cold-rolling Annealing

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Electric Field-Controlled Interfacial Polarization Coupling in van der Waals Ferroelectric Heterojunctions

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Chinese Physics Letters 2025年第5期42卷 188-205页

作者： Wei Li HengLiu Hualing Zeng International Center for Quantum Design of Functional Materials Hefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Strongly Coupled Quantum Matter Physics Department of PhysicsChinese Academy of SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Recent advances in van der Waals(vdW) ferroelectrics have sparked the development of related heterostructures with non-volatile and field-tunable functionalities. In vdW ferroelectric heterojunctions, the interfacial electrical characteristics play a crucial role in determining their performance and functionality. In this study,we explore the interfacial polarization coupling in two-dimensional(2D) ferroelectric heterojunctions by fabricating a graphene/h-BN/CuInP_(2)S_(6)/α-In_(2)Se_(3)/Au ferroelectric field-effect transistor. By varying the gate electric field, the CuInP_(2)S_(6)/α-In_(2)Se_(3) heterojunction displays distinct interfacial polarization coupling states, resulting in significantly different electrical transport behaviors. Under strong gate electric fields, the migration of Cu ions further enhances the interfacial polarization effect, enabling continuous tuning of both the polarization state and carrier concentration in α-In_(2)Se_(3). Our findings offer valuable insights for the development of novel multifunctional devices based on 2D ferroelectric materials.

关键词： graphene ferroelectric heterojunctions interfacial polarization coupling ferroelectric fiel electric field van der waals ferroelectric heterojunctions interfacial electrical characteristics vdw ferroelectric heterojunctions

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Microstructure and mechanical properties of high-pressure sintered B_(6)O-SiC nanocomposites

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Journal of Materials science & technology 2025年第1期204卷 238-244页

作者： Bin Zhang Rongxin Sun Pan Ying Song Zhao Yitong Zou Lei Sun Zihe Li Yufei Gao Mengdong Ma Lingyu Liu Chao Liu Bo Xu Center for High Pressure Science(CHiPS) State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of Education Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Materials and Surface Technology(Ministry of Education) School of Materials Science and EngineeringXihua UniversityChengdu 610039China School of Materials Science and Engineering Faculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000China

Boron suboxide(B_(6)O)is recognized as a superhard material with a low mass density,high resistance to chemical wear,and excellent wear *** its desirable properties,the limited fracture tough-ness of B_(6)O restricts its application in industrial *** study presents the structural and me-chanical characterization of B_(6)O-SiC nanocomposites,which were synthesized via a high-pressure high-temperature sintering process of B_(6)O powders and SiC *** sintering process induced fragmen-tation of SiC whiskers,resulting in the homogenous distribution of SiC fragments within the B_(6)O *** increase in SiC content was observed to decrease the composite’s hardness,while initially reducing then enhancing its *** nanocomposites containing 20 wt%and 30 wt%SiC whiskers exhibited significant improvements in fracture toughness,averaging 6.5 MPa m^(1/2)and 7.0 MPa m^(1/2),respectively-approximately threefold the toughness of polycrystalline B_(6)O-while sustaining high hardness values of 36.3 GPa and 35.6 GPa on *** analyses revealed that the composites’superior me-chanical performance is due to the presence of strong grain boundaries,as well as a high density of nan-otwins and stacking *** findings demonstrate a viable method for producing B_(6)O-based nanocom-posites with enhanced hardness and toughness,potentially expanding their industrial applicability.

关键词： B_(6)O Ceramic nanocomposite Mechanical properties Microstructure

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Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400℃

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Journal of Materials science & technology 2024年第5期172卷 71-82页

作者： Xiang Su Yuan Lei Yang Chen Hongjie Qu Zhixiang Qi Gong Zheng Xu Liu Henggao Xiang Guang Chen National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Aviation and Mechanical Engineering Changzhou Institute of TechnologyChangzhou 213032China

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy ***,the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350℃due to coarsening and transformation of strengthening ***,we reveal that the yield strength and ultimate tensile strength of the T6 state Al-8.4Cu-2.3Ce-1.0Mn-0.5Ni-0.2Zr alloy at 400◦C increase by 34%and 44%after re-aging at 300℃for 100 h,and its thermal strength exhibits distinguished ad-vantage over traditional heat-resistant aluminum *** enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al_(20)Cu_(2)Mn_(3)phase,whose number density increases over one *** significant segregation of Ni,Ce,and Zr elements at the interfaces helps improve the thermal stability of the T *** thermostable T phase effectively strengthens the matrix by in-hibiting dislocation ***,a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300℃,which is conducive to imposing a drag on the grain boundaries at high *** finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys,which could provide expanded opportunities for higher-temperature applications.

关键词： Aluminum alloys Precipitation Thermally reinforcement phase Re-aging treatment High-temperature strength

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High-dimensional aerodynamic data modeling using a machine learning method based on a convolutional neural network

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Advances in aerodynamics 2022年第1期4卷 845-875页

作者： Bo-Wen Zan Zhong-Hua Han Chen-Zhou Xu Ming-Qi Liu Wen-Zheng Wang Institute of Aerodynamic and Multidisciplinary Design Optimization National Key Laboratory of Science and Technology On Aerodynamic Design and ResearchSchool of AeronauticsNorthwestern Polytechnical UniversityXi’an710072China Aircraft Swarm Intelligent Sensing and Cooperative Control Key Laboratory of Sichuan Province School of Aeronautics and AstronauticsUniversity of Electronic Science and Technology of ChinaChengdu611731China

Modeling high-dimensional aerodynamic data presents a significant challenge in aero-loads prediction, aerodynamic shape optimization, flight control, and simulation. This article develops a machine learning approach based on a convolutional neural network (CNN) to address this problem. A CNN can implicitly distill features underlying the data. The number of parameters to be trained can be significantly reduced because of its local connectivity and parameter-sharing properties, which is favorable for solving high-dimensional problems in which the training cost can be prohibitive. A hypersonic wing similar to the Sanger aerospace plane carrier wing is employed as the test case to demonstrate the CNN-based modeling method. First, the wing is parameterized by the free-form deformation method, and 109 variables incorporating flight status and aerodynamic shape variables are defined as model input. Second, more than 7000 sample points generated by the Latin hypercube sampling method are evaluated by performing computational fluid dynamics simulations using a Reynolds-averaged Navier-Stokes flow solver to obtain an aerodynamic database, and a CNN model is built based on the observed data. Finally, the well-trained CNN model considering both flight status and shape variables is applied to aerodynamic shape optimization to demonstrate its capability to achieve fast optimization at multiple flight statuses.

关键词： aerodynamic data modeling High-dimensional problem Machine learning Convolutional neural network Computational fluid dynamics

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