检索结果-南通市图书馆

A multi-scale framework for life reduction assessment of turbine blade caused by microstructural degradation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 186-200页

作者： Xiaoguang YANG Menglei WANG Duoqi SHI Zhenlei LI Yongsheng FAN School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China National Key laboratory of science and technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 102206China

The prolonged thermal exposure with centrifugal load results in microstructural degradation,which ultimately leads to a reduction in the fatigue and creep resistance of the turbine *** present work proposes a multi-scale framework to estimate the life reduction of turbine blades,which combines a microstructural degradation model,a two-phase constitutive model,and a microstructure-dependent fatigue and creep life reduction *** framework with multi-scale models is validated by a Single Crystal(SC)Ni-based superalloy at the microstructural length-scale and is then applied to calculate the microstructural degradation and the fatigue and creep life reduction of turbine blades under two specific service *** simulation results and quantitative analysis show that the microstructural degradation and fatigue and creep life reduction of the turbine blade are heavily influenced by the variations in the proportion of the intermediate state,namely,the maximum rotor speed status,in the two specific service *** intermediate state accelerates the microstructural degradation and leads to a reduction of the life,especially the effective fatigue life reserve due to the higher temperature and rotational speed than that of the 93%maximum rotor speed status marked as the reference *** proposed multi-scale framework provides a capable approach to analyze the reduction of the fatigue and creep life for turbine blade induced by microstructural degradation,which can assist to determine a reasonable Time Between Overhaul(TBO)of the engine.

关键词： Creep Fatigue Life reduction Microstructural degradation Multi-scale modeling Turbine blades

A Tutorial on Quantized Feedback control

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue Fu IEEE the School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control

Flow characteristics of radial inflow in impeller rear cavity with baffle plate

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 270-282页

作者： Yang BAI Xiang LUO Dongdong LIU Zeyu WU Xiaoqiang ZHANG Sipeng WANG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key laboratory of science and technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

The research purpose of this paper is to explore the influence of the baffle plate on the airflow in the rear cavity of the centrifugal impeller and optimize the performance of the secondary air system’s air bleed *** this paper,a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle *** windage torque,flow structure and pressure drop between inlet and outlet were measured *** experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33×10^(5)to 22.2×10^(5)and the range of mass flow rate coefficient was from 0.92×10^(4)to 2.92×10^(4).The results show that the static cavity and the narrow stator-rotor cavity formed by the baffle plate effectively suppress the overall swirl coefficient in the ***,the static pressure and total pressure drop in the rotor-stator cavity were *** influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence *** large turbulence parameters,the windage torque would be reduced with baffle plate,while under small turbulence parameters,the baffle plate would increase with baffle *** general,the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.

关键词： Impeller rear cavity Baffle plate Flow structure Windage torque Pressure drop

Effect of wire mesh casing treatment on axial compressor performance and stability

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 60-76页

作者： Ming ZHANG Jiaming ZHANG Jiahao HU Xu DONG Dakun SUN Xiaofeng SUN School of Energy and Power Engineering Beihang UniversityBeijing 100191China beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China National Key laboratory of science and technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China

In this paper,a kind of Wire Mesh Casing Treatment(WMCT)is proposed to improve the stable operating range of the *** contrast to the traditional circumferential groove,as for WMCT,a layer of wire mesh is laid on the surface of the circumferential *** studies were conducted on the low-speed axial flow compressor,including the groove width,axial location,and mesh *** optimum axial location for WMCT is related to its groove width.A higher wire mesh count results in a smaller compressor stall margin *** simulations were carried out to study the effect of WMCT on the flow structure of the *** wire mesh in the WMCT has a certain flow resistance,which restricts the flow into and out of the *** to the WMCT,the flow parameter in the tip region of the rotor is less sensitive to changes in the operating conditions of the *** WMCT causes the rotor tip blade loading to shift backward,inhibiting the formation of spill forward of the leakage flow,and thus improving the stability of the *** flow resistance on the groove surface is a new degree-of-freedom for the casing treatment designer.

关键词： Axial compressor Wire mesh casing treatment Tip clearance flow Stall margin Blade loading

High-temperature oxidation resistance of Si-coated C/SiC composites

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4566-4572页

作者： Jie Xiao Hua-Yue Zhang Sheng-Kai Gong Hui-Bin Xu Hong-Bo Guo School of Materials science and Engineering Beihang UniversityBeijing 100191China Key laboratory of High-Temperature Structure Materials and Protective Coatings(Ministry of Industry and Information technology) Beihang UniversityBeijing 100191China

In this paper,Si coatings were sprayed onto C/SiC composite substrates by atmospheric plasma spraying(APS).The high-temperature oxidation behavior of the substrate and coating at temperatures of 1100 and 1300℃was also *** C/SiC ceramic matrix composite will be damaged seriously and even failed due to the oxidation of carbon fibers in *** Si coating effectively improved the oxidation resistance of the C/SiC substrate in the high-temperature oxidation *** effect of the thickness of the Si coatings on the oxidation resistance was *** 150-μm coating is proved to enable the substrate to have the lowest oxidation weight loss and the best oxidation resistance after static oxidation for 5 h.

关键词： Ceramic matrix composites(CMCs) Carbon fiber Si coating Oxidation Plasma spray

Prescribed Performance Evolution control for Quadrotor Autonomous Shipboard Landing

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1151-1162页

作者： Yang Yuan Haibin Duan Zhigang Zeng State Key laboratory of Virtual Reality technology and Systems the School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100083China State Key laboratory of Virtual Reality technology and Systems the School of Automation Science and Electrical EngineeringBeihang UniversityBeijing 100083 Virtual Reality Fundamental Research laboratory Department of Mathematics and TheoriesPeng Cheng LaboratoryShenzhen 518000China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China

The shipboard landing problem for a quadrotor is addressed in this paper,where the ship trajectory tracking control issue is transformed into a stabilization control issue by building a relative position *** guarantee both transient performance and steady-state landing error,a prescribed performance evolution control(PPEC)method is developed for the relative position *** addition,a novel compensation system is proposed to expand the performance boundaries when the input saturation occurs and the error exceeds the predefined *** the wind and wave on the relative position model,an adaptive sliding mode observer(ASMO)is designed for the disturbance with unknown upper *** on the dynamic surface control framework,a shipboard landing controller integrating PPEC and ASMO is established for the quadrotor,and the relative position control error is guaranteed to be uniformly ultimately *** results have verified the feasibility and effectiveness of the proposed shipboard landing control scheme.

关键词： error integrating stabilization

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2832-2841页

作者： Yan Jiang Liang-Liang Wei Jian He Hong-Bo Guo School of Materials science and Engineering Beihang UniversityBeijing 100191China Key laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2)O_(3) Superalloy

Hybrid electromechanical properties of hetero-doped and homogeneously bonded dual-mode pressure sensor for indoor body area network node

在线全文

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第1期67卷 240-253页

作者： Junbin YU Shuai XIAN Jinbiao MU Min WANG Yin WANG Xiaojuan HOU Le ZHANG Jian HE Jiliang MU Xiujian CHOU science and technology on Electronic Test and Measurement laboratory North University of China Sichuan Aerospace Fenghuo Servo control technology Corporation

Pressure sensors are considerably important for continuous monitoring of human movement and the surrounding environment to construct a caregiving system for the elderly living *** challenge for pressure sensors that still remains is combining self-driven,comfort,and ***,an all-in-one conformal pressure sensor(ACPS) based on a homogeneous integrated triboelectric-piezoelectric hybrid sensor is *** ACPS has dual-mode sensing properties due to coupling triboelectrification and piezoelectric effect ensuring a stable response to various external ***-coated glass microspheres and polyacrylonitrile were uniformly filleted into the silicone rubber substrate using a hetero-doping method to create a stretchable electrode layer with flexible conformal characteristics and a piezoelectric layer with excellent piezoelectric properties,***,the triboelectric layer was fabricated using the same silicone rubber,allowing ACPS to be homogeneously bonded into an all-in-one structure with reliable *** allowed various functional layers to have outstanding interface characteristics and thus improve the electrical transmission *** developed ACPS had outstanding sensitivity(1.04 V/104Pa),high linearity(about 0.984),a wide measurement range(10–700 k Pa),and can accurately and continuously distinguish multiple ***,using a homemade signal processing circuit,ACPSs can be deployed in the human body and the room as indoor body area network *** successfully applied to the remote tracking of daily dynamic home life and the remote operation of small electrical equipment,these ACPSs can achieve real-time caregiving for the elderly living *** an application area desperately needed by society,this study envisions a caregiving system for the elderly living alone without violating personal privacy.

关键词： dual-mode pressure sensor homogeneous bonding all-in-onestructure indoor body area network node elderly caregiving microsystem

EmotionIC: emotional inertia and contagion-driven dependency modeling for emotion recognition in conversation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第8期67卷 130-146页

作者： Yingjian LIU Jiang LI Xiaoping WANG Zhigang ZENG School of Artificial Intelligence and Automation Huazhong University of Science and Technology Hubei Key laboratory of Brain-inspired Intelligent Systems Huazhong University of Science and Technology Key laboratory of Image Processing and Intelligent control (Huazhong university of science and technology) Ministry of Education Institute of Artificial Intelligence Huazhong University of Science and Technology

Emotion recognition in conversation(ERC) has attracted growing attention in recent years as a result of the advancement and implementation of human-computer interface technologies. In this paper,we propose an emotional inertia and contagion-driven dependency modeling approach(EmotionIC) for ERC tasks. Our EmotionIC consists of three main components, i.e., identity masked multi-head attention(IMMHA), dialogue-based gated recurrent unit(DiaGRU), and skip-chain conditional random field(SkipCRF).Compared to previous ERC models, EmotionIC can model a conversation more thoroughly at both the feature-extraction and classification levels. The proposed model attempts to integrate the advantages of attention-and recurrence-based methods at the feature-extraction level. Specifically, IMMHA is applied to capture identity-based global contextual dependencies, while Dia GRU is utilized to extract speaker-and temporal-aware local contextual information. At the classification level, SkipCRF can explicitly mine complex emotional flows from higher-order neighboring utterances in the conversation. Experimental results show that our method can significantly outperform the state-of-the-art models on four benchmark *** ablation studies confirm that our modules can effectively model emotional inertia and contagion.

关键词： emotion recognition in conversation emotional inertia and contagion multi-head attention gated recurrent unit conditional random field