To improve the computational efficiency and accuracy of multi-objective reliability estimation for aerospace engineering structural systems,the Intelligent Vectorial Surrogate Modeling(IVSM)concept is presented by fus...To improve the computational efficiency and accuracy of multi-objective reliability estimation for aerospace engineering structural systems,the Intelligent Vectorial Surrogate Modeling(IVSM)concept is presented by fusing the compact support region,surrogate modeling methods,matrix theory,and Bayesian optimization strategy.In this concept,the compact support region is employed to select effective modeling samples;the surrogate modeling methods are employed to establish a functional relationship between input variables and output responses;the matrix theory is adopted to establish the vector and cell arrays of modeling parameters and synchronously determine multi-objective limit state functions;the Bayesian optimization strategy is utilized to search for the optimal hyperparameters for modeling.Under this concept,the Intelligent Vectorial Neural Network(IVNN)method is proposed based on deep neural network to realize the reliability analysis of multi-objective aerospace engineering structural systems synchronously.The multioutput response function approximation problem and two engineering application cases(i.e.,landing gear brake system temperature and aeroengine turbine blisk multi-failures)are used to verify the applicability of IVNN method.The results indicate that the proposed approach holds advantages in modeling properties and simulation performances.The efforts of this paper can offer a valuable reference for the improvement of multi-objective reliability assessment theory.展开更多
In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, i...In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today＇s material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace GmbH ＆ Co. KG is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.展开更多
This article provides a brief overview of the teaching and research at the School of Aerospace Engineering(SAE) to celebrate the 80 th anniversary of the establishment of aeronautics as a discipline at Tsinghua Univer...This article provides a brief overview of the teaching and research at the School of Aerospace Engineering(SAE) to celebrate the 80 th anniversary of the establishment of aeronautics as a discipline at Tsinghua University. The evolution of the school, undergraduate/graduate students and faculty members, and research activities and achievements have been described. The research input including research funding and research projects are summarized, showing a diversity of funding sources and a significant growth in either sum total or spending per researcher. The achievements including publications and inter/national academic awards are also introduced. It can be seen that the level of academic publications has been growing over the past decades. In addition,four representative research achievements have been briefly described to show the scientific contributions of the school.展开更多
《Journal of Aerospace Engineering》是交流宇航工程领域前沿技术最新研究成果的科技期刊。它主要刊载各种民用和军用飞机、航天器及其支持系统的理论和应用方面的论文。该刊涉及面广,涵盖了研究、设计、发展、生产、操作、服务和维...《Journal of Aerospace Engineering》是交流宇航工程领域前沿技术最新研究成果的科技期刊。它主要刊载各种民用和军用飞机、航天器及其支持系统的理论和应用方面的论文。该刊涉及面广,涵盖了研究、设计、发展、生产、操作、服务和维修、组成和辅助设备、安全性和可靠性。刊载具体专业范围:结构和机械设计、流体力学和空气动力学、推进系统和燃料、发射和着陆系统、摩损学、水力学和气体力学、试验和性能、飞控系统和航空控制系统、机械制造和质量保证、材料学。展开更多
China Academy of Strategy on Aerospace Engineering Science and Technology (CAEST) was formally established on December 31,2011.The academy was jointly established by Chinese Academy of Engineering (CAE),China Aerospac...China Academy of Strategy on Aerospace Engineering Science and Technology (CAEST) was formally established on December 31,2011.The academy was jointly established by Chinese Academy of Engineering (CAE),China Aerospace Science展开更多
The domain of aeronautical engineering and aero-engine engineering has witnessed considerable interest in the application of machine learning(ML)and deep learning(DL)techniques,revolutionizing various aspects of the f...The domain of aeronautical engineering and aero-engine engineering has witnessed considerable interest in the application of machine learning(ML)and deep learning(DL)techniques,revolutionizing various aspects of the field.This review provides a comprehensive review of the application of ML and DL in aerospace engineering and aero-engine engineering,focusing on aircraft aerodynamics,CFD,aircraft design and aeroacoustics and for aero-engine engineering focusing on health state evaluation,component optimization,blade defect detection and combustion.The review highlights the advantages and challenges of ML methods,presenting key concepts and strategies for ML.Furthermore,in terms of technical applications,DL has the potential to be on par with ML,despite being a branch of ML.The review further emphasizes the pressing requirement for a comprehensive examination of DL techniques concerning data-driven challenges within the realms of aerospace engineering and aero-engine engineering.It introduces representative DL methods and presents their mathematical definitions and illustrative applications.展开更多
In the third decade of the 21st century,the aerospace field is evolving at an unprecedented pace towards intelligence and autonomy.As competition for space resource development intensifies,breakthroughs in near-space ...In the third decade of the 21st century,the aerospace field is evolving at an unprecedented pace towards intelligence and autonomy.As competition for space resource development intensifies,breakthroughs in near-space vehicle technology emerge,and the concept of drone swarm warfare matures,traditional rule-based and experience-driven battlefield situation awareness models are struggling to meet the demands of complex adversarial environments.This special issue brings together the latest research findings from fields such as computer science and technology,electronic engineering,and cognitive science,systematically exploring the cognitive revolution driven by the deep integration of next-generation artificial intelligence and aerospace engineering,all centered around the core theme of"Intelligent Situation Awareness"(ISA).展开更多
Good distribution of samples and weights can improve the computational accuracy and efficiency in the stochastic response analyses of aerospace problems with uncertain parameters.This work proposes a new Generalized L...Good distribution of samples and weights can improve the computational accuracy and efficiency in the stochastic response analyses of aerospace problems with uncertain parameters.This work proposes a new Generalized L2 Discrepancy based on a General Point(GL2D-GP)for generating samples and their corresponding weights.The proposed GL2D-GP is an extension of the existing discrepancy by introducing the non-same weights and a smaller box to measure probability errors.Minimizing the GL2D-GP can yield a weight optimization formula that generates a set of optimal non-identical weights for a given sample set.Through minimizing the GL2D-GP assigned to the set of optimal non-same weights,a new sample and weight generation method is developed.In the proposed method,the samples can be easily generated in terms of the generalized Halton formula with a series of optimal permutation vectors which are found by the intelligent evolutionary algorithm.Once the sample set is obtained,the optimal weights can be generated in terms of the weight optimization formula.Five numerical examples are presented to verify the high accuracy,efficiency,and strong robustness of the proposed sample generation method based on GL2D-GP.展开更多
China's aerospace industry is facing a major task of increasing the reform of aerospace management system and speeding up civil-military integration, which leads to an urgent demand for new aerospace think tank pr...China's aerospace industry is facing a major task of increasing the reform of aerospace management system and speeding up civil-military integration, which leads to an urgent demand for new aerospace think tank products. Thankfully, with "information space" as the carrier, the "systems science" as the guidance, and QIAN Xuesen's "metasynthetic wisdom system" as the core, QIAN Xuesen think tank provides the decision support for China to develop an aerospace knowledge economy and to continuously enhance the "space soft power". In this paper, the framework of the meta-synthetic wisdom system guided by systems science is presented, the relationship between basic ideas of QIAN Xuesen think tank and meta-synthetic wisdom system is explained and the construction items of aerospace hall of the workshop for meta-synthetic engineering(aerospace HWMSE) are analyzed.展开更多
The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had bee...The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had been stored for three years展开更多
Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori at...Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori attitude information replacing the code measurements to enhance the successful rate for ambiguity resolution.However,there exists a key limitation that this method relies on considerable Monte Carlo sampling particles to construct the pdf of ambiguities,resulting in significant computational burdens.To address this limitation,this paper provides a rapid single-epoch GNSS attitude determination method based on a priori attitude information.It utilizes a second-order Taylor expansion to analytically estimate the covariance of the baseline conditioned on a priori attitude information.This is followed by deriving the float solution and covariance of ambiguities,which are then processed using the standard LAMBDA method for integer ambiguity resolution.Experimental results demonstrate that our method is both efficient and accurate,significantly reducing computational costs compared to previous methods,thereby enhancing its applicability for GNSS-based attitude determination.展开更多
Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste hea...Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste heat and heat flux to be dissipated to maintain the devices within a safe temperature range. However, both the total heat sinks aboard and the cooling capacity of currently utilized thermal control strategy are severely limited, which threatens the lifetime of the on-board equipment and even the entire flight system and shrink the vehicle’s flight time and range. Facing these thermal challenges, the USA proposed the program of "INVENT" to maximize utilities of the available heat sinks and enhance the cooling ability of thermal control strategies. Following the efforts done by the USA researchers, scientists in China fought their ways to develop thermal management technologies for Chinese advanced energy-optimized airplanes and spacecraft. This paper elaborates the available on-board heat sinks and aerospace thermal management systems using both active and passive technologies not confined to the technology in China. Subsequently, active thermal management technologies in China including fuel thermal management system, environment control system, non-fuel liquid cooling strategy are reviewed. At last, space thermal control technologies used in Chinese Space Station and Chang’e-3 and to be used in Chang’e-5 are introduced.Key issues to be solved are also identified, which could facilitate the development of aerospace thermal control techniques across the world.展开更多
In the modern aviation industry,accurate prediction of complex flow fields is of great significance for optimizing blade design and improving engine performance.Although traditional computational fluid dynamics(CFD)me...In the modern aviation industry,accurate prediction of complex flow fields is of great significance for optimizing blade design and improving engine performance.Although traditional computational fluid dynamics(CFD)methods can provide highprecision flow field information,they have long calculation time and high resource consumption,making it difficult to meet the rapid response requirements of engineering practice.As an emerging machine learning model,neural networks have gradually become an effective tool for flow field prediction with their powerful nonlinear mapping capabilities and high computational efficiency.This paper aims to combine machine learning technology to construct an efficient and accurate flow field prediction model method,and introduce new theoretical support for the design and optimization of aircraft engines.This paper first explains the basic concepts of machine learning and the shortcomings of current flow field prediction methods.Then,through three cases,the basic principles and application process of neural networks are introduced,including BP neural network,RBF neural network and UNet neural network methods,and the current status and superiority of neural networks in complex flow field prediction are analyzed in detail,providing an important reference for promoting the informatization and intelligent development of the aviation manufacturing industry.展开更多
The utilization of pressure vessels in aerospace applications is manifold.In this work,fnite element analysis（FEA）has been carried out using ANSYS software package with 2D axisymmetric model to access the failure pr...The utilization of pressure vessels in aerospace applications is manifold.In this work,fnite element analysis（FEA）has been carried out using ANSYS software package with 2D axisymmetric model to access the failure pressure of cylindrical pressure vessel made of ASTM A36 carbon steel having weld-induced residual stresses.To fnd out the effect of residual stresses on failure pressure,frst an elasto-plastic analysis is performed to fnd out the failure pressure of pressure vessel not having residual stresses.Then a thermo-mechanical fnite element analysis is performed to assess the residual stresses developed in the pressure vessel during welding.Finally one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual stresses.This analysis indicates reduction in the failure pressure due to unfavorable residual stresses.展开更多
In this paper, based on the mixed-type theory developed by the same authors, a theoretical analysis is presented for the stability of laminated composite circular conical shells under external pressure. The formulas f...In this paper, based on the mixed-type theory developed by the same authors, a theoretical analysis is presented for the stability of laminated composite circular conical shells under external pressure. The formulas for critical external pressure are obtained by using the potential energy variation principle. Very good agreement is shown between the theoretical prediction of critical external pressure and the experimental data. Finally, the influence of some parameters on critical external pressure is discussed numerically. The mixed-type theory developed by the same authors and the results obtained in this paper are very useful in aerospace engineering design.展开更多
This article is intended as a summary of a new area of study on the History of the Portuguese Aeronautics and Aerospace and addresses issues such as: the forthcoming of the aircraft at Portugal, its military and civil...This article is intended as a summary of a new area of study on the History of the Portuguese Aeronautics and Aerospace and addresses issues such as: the forthcoming of the aircraft at Portugal, its military and civilian use;the scope of early days concerning Portuguese intercontinental flights and their authors;the development of air navigation devices by Portuguese inventors in the 1920s and 30s;the Aeronautics industry and the need to develop expertise in Aeronautical/Aerospace Engineering in Portugal during the centuries XX and XXI.展开更多
According to the characteristic of cruise missiles,navigation point setting is simplified,and the principle of route planning for saturation attack and a concept of reference route are put forward.With the help of the...According to the characteristic of cruise missiles,navigation point setting is simplified,and the principle of route planning for saturation attack and a concept of reference route are put forward.With the help of the shortest-tangent idea in route-planning and the algorithm of back reasoning from targets,a reference route algorithm is built on the shortest range and threat avoidance.Then a route-flight-time algorithm is built on navigation points.Based on the conditions of multi-direction saturation attack,a route planning algorithm of multi-direction saturation attack is built on reference route,route-flight-time,and impact azimuth.Simulation results show that the algorithm can realize missiles fired in a salvo launch reaching the target simultaneously from different directions while avoiding threat.展开更多
1 Introduction The explosive growth of the global commercial space industry has brought low-Earth orbit(LEO)satellite constellation programs,such as Starlink and Qianfan,to a pivotal stage in the evolution of space de...1 Introduction The explosive growth of the global commercial space industry has brought low-Earth orbit(LEO)satellite constellation programs,such as Starlink and Qianfan,to a pivotal stage in the evolution of space development toward commercialization.1 Traditional space missions have stringent requirements for mission risk and payload mass,while commercial satellite design emphasizes economic viability.2 This systemic transformation has not only redefined the operational framework of aerospace engineering but also opened critical pathways for the spatial application of emerging photovoltaic technologies.Perovskite solar cells(PSCs),endowed with high specific power and cost-effectiveness,have demonstrated competitive potential against silicon-based counterparts in terrestrial applications.3 Crucially,their application prospects are particularly promising in the space domain,where device mass,power density,and cost efficiency are critical design constraints.展开更多
基金supported by the National Natural Science Foundation of China(No.51875465)the Shaanxi Province Postdoctoral Research Project Funding,Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2023002)+1 种基金the Civil Aircraft Scientific Research Projectthe Fund of Shanghai Engineering Research Center of Civil Aircraft Health Monitoring(No.GCZX-2022-01).
文摘To improve the computational efficiency and accuracy of multi-objective reliability estimation for aerospace engineering structural systems,the Intelligent Vectorial Surrogate Modeling(IVSM)concept is presented by fusing the compact support region,surrogate modeling methods,matrix theory,and Bayesian optimization strategy.In this concept,the compact support region is employed to select effective modeling samples;the surrogate modeling methods are employed to establish a functional relationship between input variables and output responses;the matrix theory is adopted to establish the vector and cell arrays of modeling parameters and synchronously determine multi-objective limit state functions;the Bayesian optimization strategy is utilized to search for the optimal hyperparameters for modeling.Under this concept,the Intelligent Vectorial Neural Network(IVNN)method is proposed based on deep neural network to realize the reliability analysis of multi-objective aerospace engineering structural systems synchronously.The multioutput response function approximation problem and two engineering application cases(i.e.,landing gear brake system temperature and aeroengine turbine blisk multi-failures)are used to verify the applicability of IVNN method.The results indicate that the proposed approach holds advantages in modeling properties and simulation performances.The efforts of this paper can offer a valuable reference for the improvement of multi-objective reliability assessment theory.
文摘In this paper, the operating conditions, technical requirements, performance characteristics, design ideas, application experiences and development trends of aerospace engine bearings, including material technology, integration design and reliability, are reviewed. The development history of aerospace engine bearing is recalled briefly at first. Then today＇s material technologies and the high bearing performances of the bearings obtained through the new materials are introduced, which play important roils in the aeroengine bearing developments. The integration design ideas and practices are explained to indicate its significant advantages and importance to the aerospace engine bearings. And the reliability of the shaft-bearing system is pointed out and treated as the key requirement with goals for both engine and bearing. Finally, as it is believed that the correct design comes from practice, the pre-qualification rig testing conducted by FAG Aerospace GmbH ＆ Co. KG is briefly illustrated as an example. All these lead to the development trends of aerospace engine bearings from different aspects.
文摘This article provides a brief overview of the teaching and research at the School of Aerospace Engineering(SAE) to celebrate the 80 th anniversary of the establishment of aeronautics as a discipline at Tsinghua University. The evolution of the school, undergraduate/graduate students and faculty members, and research activities and achievements have been described. The research input including research funding and research projects are summarized, showing a diversity of funding sources and a significant growth in either sum total or spending per researcher. The achievements including publications and inter/national academic awards are also introduced. It can be seen that the level of academic publications has been growing over the past decades. In addition,four representative research achievements have been briefly described to show the scientific contributions of the school.
文摘《Journal of Aerospace Engineering》是交流宇航工程领域前沿技术最新研究成果的科技期刊。它主要刊载各种民用和军用飞机、航天器及其支持系统的理论和应用方面的论文。该刊涉及面广,涵盖了研究、设计、发展、生产、操作、服务和维修、组成和辅助设备、安全性和可靠性。刊载具体专业范围:结构和机械设计、流体力学和空气动力学、推进系统和燃料、发射和着陆系统、摩损学、水力学和气体力学、试验和性能、飞控系统和航空控制系统、机械制造和质量保证、材料学。
文摘China Academy of Strategy on Aerospace Engineering Science and Technology (CAEST) was formally established on December 31,2011.The academy was jointly established by Chinese Academy of Engineering (CAE),China Aerospace Science
文摘The domain of aeronautical engineering and aero-engine engineering has witnessed considerable interest in the application of machine learning(ML)and deep learning(DL)techniques,revolutionizing various aspects of the field.This review provides a comprehensive review of the application of ML and DL in aerospace engineering and aero-engine engineering,focusing on aircraft aerodynamics,CFD,aircraft design and aeroacoustics and for aero-engine engineering focusing on health state evaluation,component optimization,blade defect detection and combustion.The review highlights the advantages and challenges of ML methods,presenting key concepts and strategies for ML.Furthermore,in terms of technical applications,DL has the potential to be on par with ML,despite being a branch of ML.The review further emphasizes the pressing requirement for a comprehensive examination of DL techniques concerning data-driven challenges within the realms of aerospace engineering and aero-engine engineering.It introduces representative DL methods and presents their mathematical definitions and illustrative applications.
文摘In the third decade of the 21st century,the aerospace field is evolving at an unprecedented pace towards intelligence and autonomy.As competition for space resource development intensifies,breakthroughs in near-space vehicle technology emerge,and the concept of drone swarm warfare matures,traditional rule-based and experience-driven battlefield situation awareness models are struggling to meet the demands of complex adversarial environments.This special issue brings together the latest research findings from fields such as computer science and technology,electronic engineering,and cognitive science,systematically exploring the cognitive revolution driven by the deep integration of next-generation artificial intelligence and aerospace engineering,all centered around the core theme of"Intelligent Situation Awareness"(ISA).
基金the support of the National Natural Science Foundation of China(Nos.12372190,12272077)the Fundamental Research Funds for the Central Universities,China(Nos.DUT20RC(5)009,DUT20GJ216).
文摘Good distribution of samples and weights can improve the computational accuracy and efficiency in the stochastic response analyses of aerospace problems with uncertain parameters.This work proposes a new Generalized L2 Discrepancy based on a General Point(GL2D-GP)for generating samples and their corresponding weights.The proposed GL2D-GP is an extension of the existing discrepancy by introducing the non-same weights and a smaller box to measure probability errors.Minimizing the GL2D-GP can yield a weight optimization formula that generates a set of optimal non-identical weights for a given sample set.Through minimizing the GL2D-GP assigned to the set of optimal non-same weights,a new sample and weight generation method is developed.In the proposed method,the samples can be easily generated in terms of the generalized Halton formula with a series of optimal permutation vectors which are found by the intelligent evolutionary algorithm.Once the sample set is obtained,the optimal weights can be generated in terms of the weight optimization formula.Five numerical examples are presented to verify the high accuracy,efficiency,and strong robustness of the proposed sample generation method based on GL2D-GP.
文摘China's aerospace industry is facing a major task of increasing the reform of aerospace management system and speeding up civil-military integration, which leads to an urgent demand for new aerospace think tank products. Thankfully, with "information space" as the carrier, the "systems science" as the guidance, and QIAN Xuesen's "metasynthetic wisdom system" as the core, QIAN Xuesen think tank provides the decision support for China to develop an aerospace knowledge economy and to continuously enhance the "space soft power". In this paper, the framework of the meta-synthetic wisdom system guided by systems science is presented, the relationship between basic ideas of QIAN Xuesen think tank and meta-synthetic wisdom system is explained and the construction items of aerospace hall of the workshop for meta-synthetic engineering(aerospace HWMSE) are analyzed.
文摘The Academy of Aerospace Liquid Propulsion Technology (AALPT) successfully completed the long-duration captive firing test of a new generation of 120-ton thrust liquid oxygen/kerosene rocket engine. The engine had been stored for three years
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(Nos.25202520,15214523)the Fundamental Research Funds for the Central Universities,China(No.YWF-22-L-805)。
文摘Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori attitude information replacing the code measurements to enhance the successful rate for ambiguity resolution.However,there exists a key limitation that this method relies on considerable Monte Carlo sampling particles to construct the pdf of ambiguities,resulting in significant computational burdens.To address this limitation,this paper provides a rapid single-epoch GNSS attitude determination method based on a priori attitude information.It utilizes a second-order Taylor expansion to analytically estimate the covariance of the baseline conditioned on a priori attitude information.This is followed by deriving the float solution and covariance of ambiguities,which are then processed using the standard LAMBDA method for integer ambiguity resolution.Experimental results demonstrate that our method is both efficient and accurate,significantly reducing computational costs compared to previous methods,thereby enhancing its applicability for GNSS-based attitude determination.
基金supported by the Starting Foundation for Young Researchers in Yangzhou Universityfunded by the Chinese Postdoctoral Science Foundation (No. 2020M671618)。
文摘Recently, the development of modern vehicles has brought about aggressive integration and miniaturization of on-board electrical and electronic devices. It will lead to exponential growth in both the overall waste heat and heat flux to be dissipated to maintain the devices within a safe temperature range. However, both the total heat sinks aboard and the cooling capacity of currently utilized thermal control strategy are severely limited, which threatens the lifetime of the on-board equipment and even the entire flight system and shrink the vehicle’s flight time and range. Facing these thermal challenges, the USA proposed the program of "INVENT" to maximize utilities of the available heat sinks and enhance the cooling ability of thermal control strategies. Following the efforts done by the USA researchers, scientists in China fought their ways to develop thermal management technologies for Chinese advanced energy-optimized airplanes and spacecraft. This paper elaborates the available on-board heat sinks and aerospace thermal management systems using both active and passive technologies not confined to the technology in China. Subsequently, active thermal management technologies in China including fuel thermal management system, environment control system, non-fuel liquid cooling strategy are reviewed. At last, space thermal control technologies used in Chinese Space Station and Chang’e-3 and to be used in Chang’e-5 are introduced.Key issues to be solved are also identified, which could facilitate the development of aerospace thermal control techniques across the world.
文摘In the modern aviation industry,accurate prediction of complex flow fields is of great significance for optimizing blade design and improving engine performance.Although traditional computational fluid dynamics(CFD)methods can provide highprecision flow field information,they have long calculation time and high resource consumption,making it difficult to meet the rapid response requirements of engineering practice.As an emerging machine learning model,neural networks have gradually become an effective tool for flow field prediction with their powerful nonlinear mapping capabilities and high computational efficiency.This paper aims to combine machine learning technology to construct an efficient and accurate flow field prediction model method,and introduce new theoretical support for the design and optimization of aircraft engines.This paper first explains the basic concepts of machine learning and the shortcomings of current flow field prediction methods.Then,through three cases,the basic principles and application process of neural networks are introduced,including BP neural network,RBF neural network and UNet neural network methods,and the current status and superiority of neural networks in complex flow field prediction are analyzed in detail,providing an important reference for promoting the informatization and intelligent development of the aviation manufacturing industry.
文摘The utilization of pressure vessels in aerospace applications is manifold.In this work,fnite element analysis（FEA）has been carried out using ANSYS software package with 2D axisymmetric model to access the failure pressure of cylindrical pressure vessel made of ASTM A36 carbon steel having weld-induced residual stresses.To fnd out the effect of residual stresses on failure pressure,frst an elasto-plastic analysis is performed to fnd out the failure pressure of pressure vessel not having residual stresses.Then a thermo-mechanical fnite element analysis is performed to assess the residual stresses developed in the pressure vessel during welding.Finally one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual stresses.This analysis indicates reduction in the failure pressure due to unfavorable residual stresses.
基金The Project Supported by the Doctoral Research Foundation of the State Education Commission of China
文摘In this paper, based on the mixed-type theory developed by the same authors, a theoretical analysis is presented for the stability of laminated composite circular conical shells under external pressure. The formulas for critical external pressure are obtained by using the potential energy variation principle. Very good agreement is shown between the theoretical prediction of critical external pressure and the experimental data. Finally, the influence of some parameters on critical external pressure is discussed numerically. The mixed-type theory developed by the same authors and the results obtained in this paper are very useful in aerospace engineering design.
文摘This article is intended as a summary of a new area of study on the History of the Portuguese Aeronautics and Aerospace and addresses issues such as: the forthcoming of the aircraft at Portugal, its military and civilian use;the scope of early days concerning Portuguese intercontinental flights and their authors;the development of air navigation devices by Portuguese inventors in the 1920s and 30s;the Aeronautics industry and the need to develop expertise in Aeronautical/Aerospace Engineering in Portugal during the centuries XX and XXI.
基金supported by the Aeronautical Science Foundation of China (20085584010)
文摘According to the characteristic of cruise missiles,navigation point setting is simplified,and the principle of route planning for saturation attack and a concept of reference route are put forward.With the help of the shortest-tangent idea in route-planning and the algorithm of back reasoning from targets,a reference route algorithm is built on the shortest range and threat avoidance.Then a route-flight-time algorithm is built on navigation points.Based on the conditions of multi-direction saturation attack,a route planning algorithm of multi-direction saturation attack is built on reference route,route-flight-time,and impact azimuth.Simulation results show that the algorithm can realize missiles fired in a salvo launch reaching the target simultaneously from different directions while avoiding threat.
文摘1 Introduction The explosive growth of the global commercial space industry has brought low-Earth orbit(LEO)satellite constellation programs,such as Starlink and Qianfan,to a pivotal stage in the evolution of space development toward commercialization.1 Traditional space missions have stringent requirements for mission risk and payload mass,while commercial satellite design emphasizes economic viability.2 This systemic transformation has not only redefined the operational framework of aerospace engineering but also opened critical pathways for the spatial application of emerging photovoltaic technologies.Perovskite solar cells(PSCs),endowed with high specific power and cost-effectiveness,have demonstrated competitive potential against silicon-based counterparts in terrestrial applications.3 Crucially,their application prospects are particularly promising in the space domain,where device mass,power density,and cost efficiency are critical design constraints.
