检索结果-南通市图书馆

Chinese Journal of aeronautics 2023年第3期36卷 161-170页

作者： Xuming NIU Qi LU Zhigang SUN Yingdong SONG Jiangsu Province Key Laboratory of aerospace Power System and College of Energy and Power engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Laboratory of Aero-engine Thermal Environment and Structure Ministry of Industry and Information Technology College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China College of Energy and Power engineering and State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Comprehensive Mission Spectrum(CMS)of an Aero-engine can reflect the usage characteristics of the engine.It can provide load input for engine life prediction and accelerated mission test.In this paper,a novel compilation method of CMS of Aero-engine maneuvering load based on mission segment is proposed.Firstly,the use-related Typical Mission Segment(TMS)of maneuvering load is divided and identified according to spectral characteristics.Secondly,the mathematical model of different kinds of TMS are established based on stochastic process theory.Finally,the CMS of maneuvering load is compiled based on TMS.The proposed method can accurately quantify the compilation of CMS.The compiled CMS shows good agreement with the original load spectrum.According to damage consistency inspection,the compiled CMS is consistent with the damage caused by the original load spectrum in terms of low cycle fatigue.

关键词： Aero-engine Comprehensive mission spectrum Maneuvering load Spectrum compilation Typical mission segment

Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for Aero-engine cooling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2022年第12期35卷 32-46页

作者： Yinlong LIU Guoqiang XU Yanchen FU Jie WEN Shaoshuai QI Lulu LYU Research Institute of Aero-engine Beihang UniversityBeijing 100083China National Key Laboratory of Science and Technology on Aero-engine aero-thermodynamics Beihang UniversityBeijing 100083China School of Energy and Power engineering Beihang UniversityBeijing 100083China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China China aerospace aerodynamics Technology Research Institute Beijing 100074China AECC Commercial Aircraft engine Co. Ltd.Shanghai 200241China

This study explores the design,analysis,and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number Aero-engines.In high speed flight,the compressor bleed air used to cool high temperature turbine blades and other hot components is too hot.Hence,aviation kerosene is applied to precool the compressor bleed air by means of novel air–fuel heat exchangers.Three light and compact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured,with little difference existing in aspects of tube pitches and outer diameters among three heat exchangers.The fuel flows inside a series of parallel stainless serpentine tubes(outer diameter:2.2,1.8,1.4 mm with 0.2 mm thickness),while the air externally flows normal to tube bundles and countercurrent with fuel.Experimental studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet temperatures.Non-isothermal measurements have also been performed to research the effect of heat transfer on pressure drops.The experimental results show that inlet temperatures have significant influence on pressure drops,and higher temperatures lead to higher pressure drops at the same mass flow rate.The hydraulic resistance coefficient decreases quickly with Reynolds number,and the descent rate slows down when Re>6000 for all three heat exchangers.Additionally,the pressure drop on heat transfer states is less than that on isothermal states for the same average temperatures.Moreover,the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches,and an asymmetric M-shaped velocity profile is generated in the crosssection of sector channels.

关键词： Aero-engine Heat exchanger Heat transfer Pressure drop Serpentine tube

Optimization of Aero-engine pipeline for avoiding vibration based on length adjustment of straight-line segment

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical engineering 2022年第1期17卷 100-116页

作者： Wenhao JI Wei SUN Donghai WANG Zhonghua LIU School of Mechanical engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of aero-Propulsion Systems Department of Education of China Northeastern UniversityShenyang 110819China Shenyang Area 2nd Military Representative Room of Air Force Equipment Department Shenyang 110043China

In the design and troubleshooting of Aero-engine pipeline,the vibration reduction of the pipeline system is often achieved by adjusting the hoop layout,provided that the shape of pipeline remains unchanged.However,in reality,the pipeline system with the best antivibration performance may be obtained only by adjusting the pipeline shape.In this paper,a typical spatial pipeline is taken as the research object,the length of straight-line segment is taken as the design variable,and an innovative optimization method of avoiding vibration of Aero-engine pipeline is proposed.The relationship between straight-line segment length and parameters that determine the geometric characteristics of the pipeline,such as the position of key reference points,bending angle,and hoop position,are derived in detail.Based on this,the parametric finite element model of the pipeline system is established.Taking the maximum first-order natural frequency of pipeline as the optimization objective and introducing process constraints and vibration avoidance constraints,the optimization model of the pipeline system is established.The genetic algorithm and the golden section algorithm are selected to solve the optimization model,and the relevant solution procedure is described in detail.Finally,two kinds of pipelines with different total lengths are selected to carry out a case study.Based on the analysis of the influence of straight-line segment length on the vibration characteristics of the pipeline system,the optimization methods developed in this paper are demonstrated.Results show that the developed optimization method can obtain the optimal single value or interval of the straight-line segment length while avoiding the excitation frequency.In addition,the optimization efficiency of the golden section algorithm is remarkably higher than that of the genetic algorithm for length optimization of a single straight-line segment.

关键词： length adjustment spatial pipeline Aero-engine vibration avoidance optimization genetic algorithm golden section algorithm

Effects of pressure oscillation on aerodynamic characteristics in an Aero-engine combustor

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 2021年第2期34卷 454-465页

作者： Hao QIN Guanqiong TANG Xionghui WANG Design and Research Center AECC Commercial Aircraft Engine Co.Ltd.Shanghai 200241China

The effects of pressure oscillation on aerodynamic characteristics in an Aero-engine combustor are investigated. A combustor test rig is designed to simulate the pressure drop characteristics of a practical annular combustor. The pressure drop characteristics are firstly measured under atmosphere condition with non-reacting flow(or cold flow), and the air mass flow proportion of each component(dome/liner) are obtained;these properties are base lines for comparison with combustion state. The combustion tests are then carried out under conditions of inlet temperature 340–450 K, fuel air ratio 0.010–0.028. The stability map and the oscillation frequencies are obtained in the tests, the results show that pressure oscillation amplitude increases with the increase of fuel air ratio. Phase trajectory reconstruction is applied to classify the pressure oscillation motion;there are three motions captured in the tests including: ‘‘disk", ‘‘ring" and ‘‘cluster". The pressure drops across the dome under strong pressure oscillation are distinctly divergent from the cold flow, and the changes of pressure drops are mainly affected by pressure oscillation amplitude, but is less influenced by pressure oscillation motion nor oscillation frequencies. Based on the mass flow conservation, the reduction of effective flow area of combustor under strong pressure oscillation is demonstrated. Liner wall temperatures are analyzed through Multiple Linear Regression(MLR)method to estimate the reduction of the air mass flow proportion of the liner cooling under strong pressure oscillation. Finally, the air mass flow proportions of each component under strong pressure oscillation are estimated, the results show that the pressure oscillation motion also has influence on air mass flow proportion.

关键词： aerodynamic Aero-engine Combustor Multiple Linear Regression Nonlinear Phase trajectory reconstruction Pressure oscillation

Group-based multiple pipe routing method for Aero-engine focusing on parallel layout

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical engineering 2021年第4期16卷 798-813页

作者： Hexiang YUAN Jiapeng YU Duo JIA Qiang LIU Hui MA School of Mechanical engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of aero-Propulsion System(Ministry of Education) Northeastern UniversityShenyang 110819China Shenyang engine Research Institute of AECC Shenyang 110015China School of Information and Control engineering Liaoning Petrochemical UniversityFushun 113001China

External pipe routing for Aero-engine in limited three-dimensional space is a typical nondetermini-stic polynomial hard problem,where the parallel layout of pipes plays an important role in improving the utilization of layout space,facilitating pipe assembly,and maintenance.This paper presents an automatic multiple pipe routing method for Aero-engine that focuses on parallel layout.The compressed visibility graph construction algorithm is proposed first to determine rapidly the rough path and interference relationship of the pipes to be routed.Based on these rough paths,the information of pipe grouping and sequencing are obtained according to the difference degree and interference degree,respectively.Subsequently,a coevolutionary improved differential evolution algorithm,which adopts the coevolutionary strategy,is used to solve multiple pipe layout optimization problem.By using this algorithm,pipes in the same group share the layout space information with one another,and the optimal layout solution of pipes in this group can be obtained in the same evolutionary progress.Furthermore,to eliminate the minor angle deviation of parallel pipes that would cause assembly stress in actual assembly,an accurate parallelization processing method based on the simulated annealing algorithm is proposed.Finally,the simulation results on an Aero-engine demonstrate the feasibility and effectiveness of the proposed method.

关键词： multiple pipe routing optimization algorithm Aero-engine pipe grouping parallel layout

Four-axis trochoidal toolpath planning for rough milling of Aero-engine blisks

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 2019年第8期32卷 2009-2016页

作者： Ming LUO Ce HAH Hafiz M.HAFEEZ Key Laboratory of Contemporary Design and Integrated Manufacturing Technology(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Beijing Jingdiao Group Co. Ltd.Beijing 102308China

The Blade Integrated Disk(Blisk) is one of the key components in the Aero-engine, it is generally manufactured by the multi-axis milling and almost 90% raw materials are removed. To avoid the full immersion of a cutter in the rough machining of a blisk channel, the trochoidal milling is a promising strategy since it can keep a small immersion angle in the rough milling process while maintaining the high machining efficiency. However, while toolpaths are being planned for the trochoidal milling process, the conventional methods are mainly for the planar machining area with fixed tool orientations, which cannot be used for complex channels where the multi-axis machining should be employed. To this end, this paper presents a four-axis trochoidal toolpath planning method with a ball-end cutter, and thus the blisk channel can be machined efficiently.For this to happen, the trochoidal paths are planned in the parametric domain and then mapped into the physical domain, with tool orientations controlled by the quaternion interpolation method to have smooth tool movement along the toolpaths. Both geometric simulation and physical milling experiments of the proposed method have convincingly demonstrated the validation of the proposed method.

关键词： Aero-engine Blisk Machining Toolpath planning Trochoidal milling

An Aero-engine life-cycle maintenance policy optimization algorithm: Reinforcement learning approach

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2019年第9期32卷 2133-2150页

作者： Zhen LI Shisheng ZHONG Lin LIN School of Mechatronics engineering Harbin Institute of Technology

An Aero-engine maintenance policy plays a crucial role in reasonably reducing maintenance cost. An Aero-engine is a type of complex equipment with long service-life. In engineering,a hybrid maintenance strategy is adopted to improve the Aero-engine operational reliability. Thus,the long service-life and the hybrid maintenance strategy should be considered synchronously in Aero-engine maintenance policy optimization. This paper proposes an Aero-engine life-cycle maintenance policy optimization algorithm that synchronously considers the long service-life and the hybrid maintenance strategy. The reinforcement learning approach was adopted to illustrate the optimization framework, in which maintenance policy optimization was formulated as a Markov decision process. In the reinforcement learning framework, the Gauss–Seidel value iteration algorithm was adopted to optimize the maintenance policy. Compared with traditional Aero-engine maintenance policy optimization methods, the long service-life and the hybrid maintenance strategy could be addressed synchronously by the proposed algorithm. Two numerical experiments and algorithm analyses were performed to illustrate the optimization algorithm in detail.

关键词： Aero-engine Hybrid strategy Maintenance policy Optimization algorithm Reinforcement learning

Experimental study of rotating gliding arc discharge plasma-assisted combustion in an Aero-engine combustion chamber

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2019年第2期32卷 337-346页

作者： Liming HE Yi CHEN Jun DENG Jianping LEI Li FEI Pengfei LIU Science and Technology on Plasma Dynamics Laboratory Aeronautics and Astronautics Engineering CollegeAir Force Engineering University

The combustion chamber is the core component of an Aero-engine, and affects its reliability and security operation, even the performance of the aircraft. In this work, a Plasma-Assisted Combustion(PAC) test platform was developed to validate the feasibility of using PAC actuators to enhance annular combustor performance. Two plans of PAC(rotating gliding arc discharge plasma) were designed, Assisted Combustion from Primary Holes(ACPH) and Assisted Combustion from Dilution Holes(ACDH). Comparative experiments and analysis between conventional combustion and PAC were conducted to study the effects of ACPH and ACDH on the performances including average outlet temperature, combustion efficiency, pattern factor under four different excessive air coefficients(0.8, 1, 2, and 4), and lean blowout performance at different inlet airflow velocities. Experimental results show that the combustion efficiency is improved after PAC compared with that in normal conditions, and the combustion efficiency of ACPH increases2.45%, 1.49%, 1.04%, and 0.47%, while it increases 2.75%, 1.67%, 1.36%, and 0.36% under ACDH conditions. The uniformity of the outlet temperature field and the lean blowout performance are improved after PAC. Especially for ACPH, the widening of the lean blowout limit is8.3%, 12.4%, 12.8%, and 25% respectively when the inlet velocity ranges from 60 m/s to120 m/s. These results offer new perspectives for using PAC devices to enhance Aero-engine combustors' performances.

关键词： Aero-engine Assisted combustion actuator Combustion chambers Plasma-Assisted Combustion Rotating gliding arc discharge

Leakage performance of floating ring seal in cold/hot state for Aero-engine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2019年第9期32卷 2085-2094页

作者： Guoqing LI Qian ZHANG Enliang HUANG Zhijun LEI Hongwei WU Gang XU Institute of engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Research Institute of Petroleum Exploration and Development Beijing 100083China School of engineering and Technology University of HertfordshireHatfield AL109ABUnited Kingdom

Rotating experimental investigations were carried out to study the oil sealing capability of two different floating ring seals in cold/hot state for Aero-engine. High-speed Floating Ring Seal(HFRS) is a seal with the inner diameter of 83.72 mm and maximum speed of 38000 r/min, and Low-speed Floating Ring Seal(LFRS) is another seal with the inner diameter of 40.01 mm and maximum speed of 18000 r/min. In hot state, sealing air with the temperature of 371 K and oil with the temperature of 343 K was employed to model the working conditions of an Aero-engine. Comparisons between floating ring seal and labyrinth seal were done to inspect the leakage performance.More attention was paid to the critical pressure ratio where the oil leakage began. Results show that the critical pressure ratio in cold state is obviously larger than that in hot state for both seals. An underlying sealing mechanism for floating ring seal is clarified by the fluid film, which closely associates with the dimensionless parameter of clearance over rotating diameter(2 c/Dr). Another fantastic phenomenon is that the leakage coefficient in hot state, not the leakage magnitude, is unexpectedly larger than that in cold state. Overall, the leakage performance of the floating ring seal is better than the labyrinth seal.

关键词： Aero-engine Critical pressure ratio Floating ring seal Labyrinth seal Leakage Rotating

A multi-rate sensor fusion approach using information filters for estimating Aero-engine performance degradation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2019年第7期32卷 1603-1617页

作者： Feng LU Chunyu JIANG Jinquan HUANG Xiaojie QIU Jiangsu Province Key Laboratory of aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China Aviation Motor Control System Institute Aviation Industry Corporation of ChinaWuxi214063China

Gas-path performance estimation plays an important role in Aero-engine health management, and Kalman Filter(KF) is a well-known technique to estimate performance degradation. In previous studies, it is assumed that different kinds of sensors are with the same sampling rate, and they are used for state estimation by the KF simultaneously. However, it is hard to achieve state estimation using various kinds of sensor measurements at the same sampling rate due to a complex network and physical characteristic differences between sensors, especially in an advanced multisensor architecture. For this purpose, a multi-rate sensor fusion using the information filtering approach is proposed based on the square-root cubature rule, which is called Multi-rate Squareroot Cubature Information Filter(MSCIF) to track engine performance degradation. Soft measurement synchronization of the MSCIF is designed to provide a sensor fusion condition for multiple sampling rates of measurement, and a fault sensor is isolated by maximum likelihood validation before state estimation. The contribution of this paper is to supply a novel multi-rate informationfilter approach for sensor fault tolerant health estimation of an Aero-engine in a multi-sensor system. Tests are conducted for Aero-engine performance degradation estimation with multiple sampling rates of sensor measurement on both digital simulation and semi-physical experiment.Experimental results illustrate the superiority of the proposed algorithm in terms of degradation estimation accuracy and robustness to sensor failure in a multi-sensor system.

关键词： Aero-engine Cubature information filter Performance degradation Sensor fusion State estimation