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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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UAV-Assisted Data Synchronization for Digital-Twin-Enabled Vehicular Networks

UAV-Assisted Data Synchronization for Digital-Twin-Enabled V...

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2023 IEEE/CIC International Conference on Communications in China, ICCC 2023

作者： Wu, Guoquan Nie, Jiangtian Tang, Jianhang Zhang, Yang Xiao, Jiang Xiong, Zehui Yanshan University School of Information Science and Engineering China Nanyang Technological University School of Computer Science and Engineering Singapore Guizhou University State Key Laboratory of Public Big Data China Nanjing University of Aeronautics and Astronautics College of Computer Science and Technology China Huazhong University of Science and Technology School of Computer Science and Technology China Singapore University of Technology and Design Pillar of Information Systems Technology and Design Singapore

ISBN: (纸本)9798350345384

Digital twin (DT) is becoming a promising solution for vehicular networks to improve the interoperability of distributed autonomous driving systems. Mobile edge computing (MEC) has been introduced to provide low-latency services for DT-enabled vehicular networks at the edge of the network. However, it is hard to obtain the dynamic network topology for moving vehicles by the ground-based MEC system, which may deteriorate the service quality for DT synchronization. In this paper, we propose a novel unmanned aerial vehicle (UAV)-assisted synchronization framework for DT-enabled vehicular networks. With the proposed framework, an intelligent resource allocation algorithm is developed to improve UAV resource utilization and maximize the synchronization completion ratio. By leveraging an advantage actor-critic (A2C) algorithm, the synchronization decisions are obtained with low time complexity. Experiment results demonstrate that the proposed algorithm can reduce the synchronization latency and improve the synchronization completion ratio effectively. © 2023 IEEE.

关键词： Resource allocation

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Estimation of Fracture Toughness for A508-III Steel in Ductile-to-Brittle Transition Region Using a Strain-Energy–Density-Based Fracture Failure Model

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Acta Mechanica Solida Sinica 2022年第5期35卷 834-841页

作者： Yuanjun Wu Chen Bao Lixun Cai Kaiqing Wang Xiao Liu Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu610031China Science and Technology on Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu610213China

According to the assumption of intrinsic relationship between ultimate strain energy density and microcrack nucleation,this work developed a fracture failure model to estimate the fracture toughness of A508-III steel in the ductile-to-brittle transition *** fracture toughness and uniaxial tension tests at different temperatures were carried out to determine the relationship between nucleation parameter and ultimate strain energy density,from which the evolutions of fracture toughness of A508-III ferritic steel for different cumulative failure probabilities at different temperatures were *** fracture failure model can well describe the fracture toughness distribution of A508-III steel in the ductile-to-brittle transition *** with the master curve method,this model has better temperature *** is more convenient to calibrate the parameters of this model compared with the traditional Beremin model,and without complex finite element analysis.

关键词： Fracture toughness Cumulative failure probability A508-III steel Ductile-to-brittle transition region

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Particle swarm optimised fuzzy PID control method for hybrid magnetic bearings 3

Particle swarm optimised fuzzy PID control method for hybrid...

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3rd International Conference on Intelligent Mechanical and Human-Computer Interaction technology, IHCIT 2024

作者： Xiong, Feng Han, Jinchang Xu, Wenhao Li, Yan Institute of Noise & vibration Naval University of Engineering Wuhan430033 China National Key Laboratory on Ship Vibration & Noise Wuhan China Science and Technology on System Design Technology Laboratory Nuclear Power institute of China Chengdu610213 China

ISBN: (纸本)9781510683105

To enhance the control effectiveness of hybrid magnetic bearings (HMBs), this paper proposes a PSO-based fuzzy PID control algorithm. The algorithm optimizes the fuzzy controller's output parameters using the Particle Swarm Optimization technique, effectively addressing the limitations caused by fixed parameters and improving control accuracy. The effectiveness of the PSO algorithm optimization is verified through simulations of a hybrid magnetic bearing system built in Simulink. Compared to the fuzzy PID control algorithm, this method demonstrates a faster response and smaller overshoot, achieving better results in controlling the vibration displacement of rotors supported by hybrid magnetic bearings. © 2024 SPIE.

关键词： Particle swarm optimization (PSO)

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Proposal for valleytronic materials:Ferrovalley metal and valley gapless semiconductor

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Frontiers of physics 2024年第2期19卷 131-139页

作者： San-Dong Guo Yu-Ling Tao Guangzhao Wang Shaobo Chen Dong Huang Yee Sin Ang School of Electronic Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing School of Electronic Information EngineeringYangtze Normal UniversityChongqing 408100China College of Electronic and Information Engineering Anshun UniversityAnshun 561000China Science Mathematics and Technology(SMT)Singapore University of Technology and Design(SUTD)8 Somapah RoadSingapore 487372Singapore

Valleytronic materials can provide new degrees of freedom to future electronic *** this work,the concepts of the ferrovalley metal(FVM)and valley gapless semiconductor(VGS)are proposed,which can be achieved in valleytronic bilayer systems by electric field *** valleytronic bilayer systems,the interaction between out-of-plane ferroelectricity and A-type antiferromagnetism can induce layer-polarized anomalous valley Hall(LP-AVH)*** K and−K valleys of FVM are both metallic,and electron and hole carriers simultaneously *** the extreme case,the FVM can become VGS by analogizing spin gapless semiconductor(SGS).Moreover,it is proposed that the valley splitting enhancement and valley polarization reversal can be achieved by electric field engineering in valleytronic bilayer *** the bilayer RuBr_(2)as an example,our proposal is confirmed by the first-principle *** FVM and VGS can be achieved in bilayer RuBr_(2)by applying electric *** appropriate electric field range,increasing electric field can enhance valley splitting,and the valley polarization can be reversed by flipping electric field *** effectively tune valley properties by electric field in bilayer systems,the parent monolayer should possess out-of-plane magnetization,and have large valley *** results shed light on the possible role of electric field in tuning valleytronic bilayer systems,and provide a way to design the ferrovalley-related material by electric field.

关键词： valleytronics electric field bilayer

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Informative Point cloud Dataset Extraction for Classification via Gradient-based Points Moving 24

Informative Point cloud Dataset Extraction for Classificatio...

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32nd ACM International Conference on Multimedia, MM 2024

作者： Zhang, Wenxiao Wang, Ziqi Xu, Li Yang, Xun Liu, Jun University of Science and Technology of China Hefei China Wuhan University Wuhan China Singapore University of Technology and Design Singapore Singapore MoE Key Laboratory of Brain-inspired Intelligent Perception and Cognition University of Science and Technology of China Hefei China Lancaster University Lancaster United Kingdom

ISBN: (纸本)9798400706868

Point cloud plays a significant role in recent learning-based vision tasks, which contain additional information about the physical space compared to 2D images. However, such a 3D data format also results in more expensive training costs to train a sophisticated network with large 3D datasets. Previous methods for point cloud compression focus on compacting the representation of each point cloud for better storage and transmission but ignore the improvements in training efficiency. In this paper, we introduce a new open problem in the point cloud field, named point cloud condensation : Can we condense a large point cloud dataset into a much smaller synthetic dataset while preserving the important information of the original large dataset? In other words, we explore the possibility of training a network on a smaller dataset of informative point clouds extracted from the original large dataset but maintaining similar network classification performance. Training on this small synthetic dataset could largely improve the training efficiency. To achieve this goal, we propose a two-stage approach to generate the synthetic dataset. We first introduce a nearest-feature-mean based strategy to initialize the synthetic dataset, and then formulate our goal as a parameter-matching problem, which we solve by introducing a gradient-matching strategy to iteratively refine the synthetic dataset. We conduct extensive experiments on various synthetic and real-scanned 3D object classification benchmarks, showing that our synthetic dataset could achieve almost the same performance with only 5% point clouds of ScanObjectNN dataset compared to training with the full dataset. Codes are available at https://***/XLechter/PointCondensation. © 2024 ACM.

关键词： point cloud

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Ionogel electrolyte based on porous graphitic C_(3)N_(4)nanosheets for room temperature to 150℃quasi-solid-state lithium batteries

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Journal of Energy Chemistry 2025年第5期104卷 494-504页

作者： Zhaoen Liu Xueao Jiang Jiayin Chen Weijian Liu Long Zhao Yang Lv Zhiyong Li Yan Zhang Xiwen Wang Shiguo Zhang College of Energy Engineering Huanghuai UniversityZhumadian 463000HenanChina College of Materials Science and Engineering State Key Laboratory of Advanced Design and Manufacturing Technology for VehicleHunan UniversityChangsha 410082HunanChina School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007HenanChina

Ionogels,generally formed by immobilizing ionic liquids(ILs)with polymer gelators,hold considerable promise as quasi-solid-state electrolytes(QSSEs)for lithium metal batteries(LMBs)due to their high safety and electrode ***,their practical use in high-temperature LMBs suffers from the softened polymer chains of gelator at high temperatures,leading to liquid leakage and severe growth of Li ***,a novel inorganic ionogel(PCNIL)combining lithium salt-containing IL with porous graphitic carbon nitride nanosheets(PCN)is developed through direct physical *** exhibits a superior ionic conductivity(0.75 mS cm^(-1))at room temperature similar to that of neat IL electrolyte(LiIL)and a Li^(+)transference number(0.56)greatly higher than that of Li-IL(0.20).Furthermore,PCNIL maintains a temperature-independent shear storage modulus of up to 5 MPa from room temperature to 150℃.Consequently,the Li|PCNIL|Li symmetrical cell demonstrates extended reversible lithium plating/stripping over 1200 h without dendritic *** robust mechanical strength,excellent thermal stability,and electrochemical stability of PCNIL allow Li|PCNIL|LiFePO_(4)cells to operate stably in a wide temperature range of 25–150℃.

关键词： Ionogels Graphitic carbon nitride Quasi-solid-state electrolytes High temperature Lithium metal batteries

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Interlayer ferromagnetic coupling in nonmagnetic elements doped Crl_(3) thin films

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Frontiers of physics 2024年第6期19卷 61-68页

作者： Xuqi Li Xuyan Chen Shiyang Sun Huihui Zhang Haidan Sang Xiaonan Wang Shifei Qi Zhenhua Qiao College of Physics and Hebei Advanced Thin Film Laboratory Hebei Normal UniversityShijiazhuang 050024China School of Gifted Young University of Science and Technology of ChinaHefei 230026China School of Chemistry and Materials Science Hebei Normal UniversityShijiazhuang 050024China International Center for Quantum Design of Functional Materials CAS Key Laboratory of Strongly-Coupled Quantum Matter Physicsand Department of PhysicsUniversity of Science and Technology of ChinaHefei 230026China

The exploration of magnetism in two-dimensional layered materials has attracted extensive research *** the monoclinic phase Crl_(3) with interlayer antiferromagnetism,finding a static and robust way of realizing the intrinsic interlayer ferromagnetic coupling is *** this work,we study the electronic structure and magnetic properties of the nonmag-netic element(e.g.,O,S,Se,N,P,As,and C)doped bi-and triple-layer Crl_(3) systems via first-principles *** results demonstrate that O,P,S,As,and Se doped Crls bilayer can realize interlayer *** analysis shows that the interlayer ferromagnetic coupling in the doped few-layer Crls is closely related to the formation of localized spin-polarized state around the doped *** study presents that,for As-doped tri-layer Crl_(3),it can realize interlayer ferromagnetic *** work proves that nonmagnetic element doping can realize the interlayer ferromagnetically-coupled few-layer Crl_(3) while maintaining its semiconducting characteristics without introducing additional carriers.

关键词： ferromagnetism magnetic doping

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The Model Reduction Method of Grouped Blades 6

The Model Reduction Method of Grouped Blades

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6th International Conference on Mechanical, Electrical and Material Application, MEMA 2023

作者： Zheng, Zhaoli Zhao, Zhenxing Yang, Xiaohu Cao, Guangming Wu, Jun Science and Technology on Thermal Energy and Power Laboratory Wuhan Second Ship Design and Research Institute Wuhan430205 China

As an important structure in turbine machinery, grouped blades are easy to damage due to large thermal loads and centrifugal loads. Once the characteristic frequency of grouped blades is equal to or close to the frequency of the exciting forces, the vibration of the grouped blades will become very severe. Therefore, it is very important to analyze the characteristic frequency of grouped blades accurately and quickly. This article aims to investigate the model reduction method of grouped blades, which can reduce the unknowns in the dynamic equations of grouped blades. And the efficiency of the modal analysis of grouped blades can be improved. Finally, the effects of the modal truncation number on the error of the natural frequency, the modal shape confidence factor, and the calculation time are discussed. Although the structure discussed in this paper is the disk with three blades, the derived algorithm can be applied to large-scale grouped blades. The study of this paper can serve as a reference for the design and validation of the widely used blade groups in the industry. © Published under licence by IOP Publishing Ltd.

关键词： Modal analysis

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Fine grains with high-density annealing twins and precipitates inducing favorable strength and excellent plasticity in laser powder b e d fusion-fabricate d Inconel 718 via deep cryogenic and heat treatments

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Journal of Materials science & technology 2024年第20期187卷 28-48页

作者： Bo Liu Jiayu Xu Yubi Gao Yong Hu Xiaokang Yang Yutian Ding Dong Zhang Sujun Lu State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of TechnologyLanzhou 730050China School of Material Science and Engineering Lanzhou University of TechnologyLanzhou 730050China School of Electromechanics and Automobile Engineering Tianshui Normal UniversityTianshui 741001China Jinchuan Nickel Cobalt Research and Design Institute Jinchuan Group Co.LtdJinchang 737100China

Tailoring high-density annealing twins in laser powder bed fusion(LPBF)-fabricated alloys based on their intrinsic residual stress requires high annealing temperatures and/or long-term annealing,result-ing in the abnormal growth of large recrystallized grains,which is detrimental to mechanical *** work proposes a new strategy for achieving a favorable strength-plasticity synergy of the LPBF-fabricated Inconel 718 superalloy by performing a deep cryogenic treatment(DCT)with the subsequent heat treatment(including annealing and double aging)to tailor fine grains with“high-density annealing twins+precipitates”architectures and compares the obtained material with an alloy subjected to a direct heat treatment without a prior *** obtained results reveal that the additional internal stress gen-erated during DCT increases the stored energy and dislocation density,which provide a sufficient driving force for activating high-density annealing twin boundaries(63.2%)with fine grains(31.6μm)within a short annealing *** more homogeneous tailored microstructure with the“finer grains+high-density twins+precipitates”architectures decreases the mean free path of slipping dislocations,pro-moting intensive interactions with dislocations and inducing a strong strain hardening *** mul-tiple deformation modes of stacking faults coupled with Lomer-Cottrell locks,thin primary deformation twins,and secondary twins activated during tensile loading,sustaining a strong work hardening ability and delaying the plastic instability,which exhibits a high strength(yield strength of 1088 MPa and tensile strength of 1369 MPa)and excellent plasticity(elongation of 30%).This work not only describes a fea-sible method for simultaneously enhancing the strength and plasticity in additively manufactured(AM)alloys but also provides new insights into increasing the fraction of twins at a small grain size to improve the grain boundary-related properties without destroying the AM allo

关键词： Laser powder bed fusion Deep cryogenic treatment Stored energy High-density annealing twins Work hardening

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