The Aeronautical Journal (1968)最新文献_第2页

Is deep learning superior to traditional techniques in machine health monitoring applications 在机器健康监测应用中，深度学习是否优于传统技术

The Aeronautical Journal (1968) Pub Date : 2023-08-14 DOI: 10.1017/aer.2023.60

W. Wang, K. Vos, J. Taylor, C. Jenkins, B. Bala, L. Whitehead, Z. Peng

{"title":"Is deep learning superior to traditional techniques in machine health monitoring applications","authors":"W. Wang, K. Vos, J. Taylor, C. Jenkins, B. Bala, L. Whitehead, Z. Peng","doi":"10.1017/aer.2023.60","DOIUrl":"https://doi.org/10.1017/aer.2023.60","url":null,"abstract":"\u0000 In recent years, there has been significant momentum in applying deep learning (DL) to machine health monitoring (MHM). It has been widely claimed that DL methodologies are superior to more traditional techniques in this area. This paper aims to investigate this claim by analysing a real-world dataset of helicopter sensor faults provided by Airbus. Specifically, we will address the problem of machine sensor health unsupervised classification. In a 2019 worldwide competition hosted by Airbus, Fujitsu Systems Europe (FSE) won first prize by achieving an F1-score of 93% using a DL model based on generative adversarial networks (GAN). In another comprehensive study, various modified and existing image encoding methods were compared for the convolutional auto-encoder (CAE) model. The best classification result was achieved using the scalogram as the image encoding method, with an F1-score of 91%. In this paper, we use these two studies as benchmarks to compare with basic statistical analysis methods and the one-class supporting vector machine (SVM). Our comparative study demonstrates that while DL-based techniques have great potential, they are not always superior to traditional methods. We therefore recommend that all future published studies of applying DL methods to MHM include appropriately selected traditional reference methods, wherever possible.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81835311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-fidelity and multi-objective aerodynamic short nacelle shape optimisation under different flight conditions 不同飞行条件下多保真度多目标气动短机舱外形优化

The Aeronautical Journal (1968) Pub Date : 2023-08-09 DOI: 10.1017/aer.2023.66

G. Tao, W. Wang, Z. Ye, Y.N. Wang, J.Q. Luo, J. Cui

{"title":"Multi-fidelity and multi-objective aerodynamic short nacelle shape optimisation under different flight conditions","authors":"G. Tao, W. Wang, Z. Ye, Y.N. Wang, J.Q. Luo, J. Cui","doi":"10.1017/aer.2023.66","DOIUrl":"https://doi.org/10.1017/aer.2023.66","url":null,"abstract":"Throughout the course of a flight mission, a range of aerodynamic conditions, including design-point conditions and off-design conditions, are encountered. As the bypass ratio increases and the fan-pressure ratio decreases to reduce the engine’s specific fuel consumption, the engine diameters increase, which results in an increase in the nacelle weight and overall drag. To reduce its weight and drag, a shorter nacelle with a length-to-diameter ratio $L/D = 0.35$ is investigated. In this study, an adaptive cokriging-based multi-objective optimisation method is applied to the design of a short aero-engine nacelle. Two nacelle performance metrics were employed as the objective functions for the optimisation routine. The cruise drag coefficient is evaluated under cruise conditions, whereas the intake pressure recovery is evaluated under takeoff conditions. The cokriging metamodel are refined using an effective infilling strategy, where high-fidelity samples are infilled via the modified Pareto fitness, and low-fidelity samples are infilled via the Pareto front. By combining parameterised geometry generation, automated mesh generation, numerical simulations, surrogate model construction, Pareto front exploration based on the non-dominated sorting genetic algorithm-II and sample infilling, an integrated multi-objective optimisation framework for short aero-engine nacelles is developed. Two-objective and three-objective test functions are used to validate the effectiveness of the proposed framework. After the optimisation process, a set of non-dominated nacelle designs is obtained with better aerodynamic performance than the original design, demonstrating the effectiveness of the optimisation framework. Compared with the kriging-based optimisation framework, the cokriging-based optimisation framework outperforms the single-fidelity method with a higher hypervolume value at the same number of iteration loops.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87415629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design-oriented dynamic model of deployable fin under time-varying elevated temperature environment 时变高温环境下面向设计的可展开鳍动态模型

The Aeronautical Journal (1968) Pub Date : 2023-08-07 DOI: 10.1017/aer.2023.69

H. Ren, Y. Wang, L. Wang, J.B. Zhou, H.J. Chang, Y. Cai, B. Lei

{"title":"Design-oriented dynamic model of deployable fin under time-varying elevated temperature environment","authors":"H. Ren, Y. Wang, L. Wang, J.B. Zhou, H.J. Chang, Y. Cai, B. Lei","doi":"10.1017/aer.2023.69","DOIUrl":"https://doi.org/10.1017/aer.2023.69","url":null,"abstract":"\u0000 Coupling of clearance joint and harsh aerodynamic heating environment is an inevitable nonlinear factor in folding mechanism of the fin of high-speed aircrafts that remarkably modifies natural frequencies and modes of vibration from the initial design state. However, accurately predicting dynamic properties of deployable fin with full consideration of these effects is not common industry practice. A practical semi-analytical model based on Hertz contact theory and ESDU-78035 model is proposed in this study to investigate high-temperature connection stiffness of local hinged–locked mechanisms. Material property degradation and clearance variation caused by thermal expansion are comprehensively considered and quantified in this model. Vibration characteristics of the assembled deployable fin are then solved using finite element method (FEM). The real-time evolutionary process of thermal mode of the fin is discussed. And natural frequencies of fixed-value and time-varying connection stiffness are compared. The simulation results of this study demonstrate that the relative error of structure temperature between the sequential approach and fully coupled simulations is less than 6.98%. The connection stiffness (slope of the load-displacement curve) of the folding mechanism under high temperature conditions decreases by 3.52%, and the variation is mainly caused by the degradation of the elastic modulus of the material, while the clearance change due to the thermal expansion has no significant effect on the slope. The natural frequency of the deployable fin exhibits an inverse correlation with the temperature change trend, and the first three frequencies decrease by 1.67, 7.75, and 16.28 Hz compared to the initial value, respectively.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"78 12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87906823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A methodology to determine the precision uncertainty in gas turbine engine cycle models 燃气轮机循环模型精度不确定度的确定方法

The Aeronautical Journal (1968) Pub Date : 2023-08-04 DOI: 10.1017/aer.2023.64

M. D. J. Gurrola Arrieta, R. Botez

{"title":"A methodology to determine the precision uncertainty in gas turbine engine cycle models","authors":"M. D. J. Gurrola Arrieta, R. Botez","doi":"10.1017/aer.2023.64","DOIUrl":"https://doi.org/10.1017/aer.2023.64","url":null,"abstract":"\u0000 This paper proposes a methodology to define and quantify the precision uncertainties in aerothermodynamic cycle model comparisons. The total uncertainty depends on biases and random errors commonly found in such comparisons. These biases and random errors are classified and discussed based on observations found in the literature. The biases account for effects such as differences in model inputs, the configurations being simulated, and thermodynamic packages. Random errors consider the effects on the physics modeling and numerical methods used in cycle models. The methodology is applied to a comparison of two cycle models, designated as the model subject to comparison and reference model, respectively. The former is the so-called Aerothermodynamic Generic Cycle Model developed in-house at the Laboratory of Applied Research in Active Control, Avionics and AeroServoElasticity (LARCASE); the latter is an equivalent model programmed in the Numerical Propulsion System Simulation (NPSS). The proposed methodology is intended to quantify the bias and random errors effects on different cycle parameters of interest, such as thrust, specific fuel consumption, among others. Each bias and random errors are determined by deliberately preventing the effects from other biases and random errors. The methodology presented in this paper can be extended to other cycle model comparisons. Moreover, the uncertainty figures derived in this work are recommended to be used in other model comparisons when no better reference is available.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87007176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Control of the boundary layer on compressor blade suction surfaces with the momentum jet 动量射流对压气机叶片吸力面边界层的控制

The Aeronautical Journal (1968) Pub Date : 2023-08-03 DOI: 10.1017/aer.2023.67

H. Zheng, Z. Zhou, L. Liu

{"title":"Control of the boundary layer on compressor blade suction surfaces with the momentum jet","authors":"H. Zheng, Z. Zhou, L. Liu","doi":"10.1017/aer.2023.67","DOIUrl":"https://doi.org/10.1017/aer.2023.67","url":null,"abstract":"\u0000 The boundary layer thickness on a compressor blade suction surface increases rapidly under a adverse pressure gradient and even separates from the blade surface. This paper proposes a novel method for developing the slot inside the blade, with the inlet of the slot located at the leading edge of the blade and the outlet located at the suction surface, using the momentum of the incoming flow to form a high velocity jet to control the boundary layer on the suction surface. For a plane cascade with a diffusion factor of 0.45, the effects of the main slot parametres (such as the shape of the slot and the positions of the slot inlet and outlet) on the flow in the slot, the flow field and the aerodynamic performance of the cascade were investigated with a numerical method. When the aerodynamic performance of cascades with slotted and unslotted blades was compared, it was found that a reasonable slot structure can effectively inhibit the development of the boundary layer on the blade suction surface and greatly improve the aerodynamic performance of the cascade. Based on the influence of the slot parametres of the above cascade, the slot of a plane cascade with a diffusion factor of 0.60 was designed. The numerical calculation results show that the slotted cascade with a diffusion factor of 0.60 outperformed the slotted cascade with a diffusion factor of 0.45. This result showed that the higher the cascade load, the greater the performance improvement from slotting. Furthermore, the unslotted and slotted cascades were tested, and the test results agreed well with the calculations. The aerodynamic performance of the slotted cascade was better than that of the unslotted cascade, which verifies the accuracy of the calculation method and the feasibility of blade slotting for suppressing the development of boundary layers on suction surfaces and reducing flow loss.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80282100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect on damage of aircraft windshield impacted by light UAV with different postures 不同姿态轻型无人机对飞机挡风玻璃冲击损伤的影响

The Aeronautical Journal (1968) Pub Date : 2023-08-03 DOI: 10.1017/aer.2023.65

X.H. Lu, Y.C. Zhang, Z. Zhang

{"title":"Effect on damage of aircraft windshield impacted by light UAV with different postures","authors":"X.H. Lu, Y.C. Zhang, Z. Zhang","doi":"10.1017/aer.2023.65","DOIUrl":"https://doi.org/10.1017/aer.2023.65","url":null,"abstract":"\u0000 To study the performance of the main windshield of a commercial aircraft that has been verified to be airworthy by bird-strike tests against unmanned aerial vehicle (UAV) impact at high-speed, a typical light UAV with various possible flight postures and the main windshield of a commercial aircraft are considered. The transient impact responses at critical moments, energy change and contact force of a multi-layer windshield impacted by a UAV with different postures are investigated using a simulation method based on the models verified by the high-speed impact test between the whole UAV and the full-size nose. This study shows that the flight posture of the UAV has a significant effect on the damage to the windshield. When the abdomen of a typical light UAV maintains a posture parallel to the plane of the windshield, the high-speed impact would cause catastrophic damage to the windshield and no longer be airworthy. Simultaneously, the damage to the aircraft windshield caused by UAV collision is far more serious than that caused by bird strikes under similar collision conditions. The mass-concentrated components of the UAV and their high-hardness characteristics are the main factors of affecting multi-layer glass of windshield damage. The degree of damage to the windshield is positively related to the absorbed energy rather than the impact contact force. In this study, the impact simulation results between the windshield and UAV with different flight postures are verified qualitatively by testing, which provides a rational understanding and technical pre-research support for emerging and increasingly frequent potential safety hazards in air transport practice.","PeriodicalId":22567,"journal":{"name":"The Aeronautical Journal (1968)","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90053755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prioritising paths: An improved cost function for local path planning for UAV in medical applications 路径优先化:医疗应用中无人机局部路径规划的改进成本函数

The Aeronautical Journal (1968) Pub Date : 2023-08-02 DOI: 10.1017/aer.2023.68

A. Thoma, K. Thomessen, A. Gardi, A. Fisher, C. Braun

引用次数: 0

Experimental evaluation of the drag curves of small fixed wing UAVs 小型固定翼无人机阻力曲线的实验评估

The Aeronautical Journal (1968) Pub Date : 2023-07-27 DOI: 10.1017/aer.2023.61

A. Weishäupl, L. McLay, A. Sóbester

引用次数: 0

Output constrained neural adaptive control for a class of KKVs with non-affine inputs and unmodeled dynamics 一类具有非仿射输入和未建模动力学的kkv的输出约束神经自适应控制

The Aeronautical Journal (1968) Pub Date : 2023-07-26 DOI: 10.1017/aer.2023.44

X. Ning, J. Liu, Z. Wang, C. Luo

引用次数: 0

Establishing best practices in the use of an upgraded airborne teaching laboratory 建立使用升级后的机载教学实验室的最佳做法

The Aeronautical Journal (1968) Pub Date : 2023-07-25 DOI: 10.1017/aer.2023.47

S. Daniels, G. Braithwaite, G. Gratton

引用次数: 0