Chinese Journal of Aeronautics最新文献

{"title":"Fluid-structure interaction simulation for multi-body flexible morphing structures","authors":"Wenzhi GUO ,&nbsp;Yongtao SHUI ,&nbsp;Lu NIE ,&nbsp;Gang CHEN","doi":"10.1016/j.cja.2023.09.009","DOIUrl":"10.1016/j.cja.2023.09.009","url":null,"abstract":"<div><p>The multi-body flexible morphing airfoil can improve the aerodynamic characteristics based on different flight missions continuously. Recently researches have focused on the unsteady aerodynamic characteristics of flexible wings under passive actuation. However, the unsteady aerodynamic characteristics with the fluid–structure interaction effects in the multi-body active actuation process of morphing airfoil deserve further investigation. In this paper, a fluid–structure coupled simulation method for multi-body flexible morphing airfoil with active actuation subsystem was investigated, and the aerodynamic characteristics during deformation were compared with different skin flexibility, flow field environment, actuation mode and actuation time. The numerical results show that for the steady aerodynamic, the skin flexibility can improve the stability efficiency. In the unsteady process, the change trend of the transient lift coefficient and pitching moment are consistent with those of the active drive characteristics, while the instantaneous lift-drag ratio coefficient is greatly affected by the driving mode and can be improved by increasing the driving duration.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 2","pages":"Pages 137-147"},"PeriodicalIF":5.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003138/pdfft?md5=0ac8fee9a3a386b084063221e2547760&pid=1-s2.0-S1000936123003138-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135299081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation and modeling of sweep effects on inlet flow field of axial compressor cascades","authors":"Jiancheng ZHANG ,&nbsp;Donghai JIN ,&nbsp;Xingmin GUI","doi":"10.1016/j.cja.2023.10.020","DOIUrl":"10.1016/j.cja.2023.10.020","url":null,"abstract":"<div><p>Swept blades are widely utilized in transonic compressors/fans and provide high load, high through-flow, high efficiency, and adequate stall margin. However, there is limited quantitative research on the mechanism of the effect of swept blades on the flow field, resulting in a lack of direct quantitative guidance for the design and analysis of swept blades in fans/compressors. To better understand this mechanism, this study employs a reduced-dimensional force equilibrium method to analyze more than 1500 swept cascades data. Results verify that circumferential fluctuation terms are responsible for inducing radial migration in the inlet airflow field of the swept blade, resulting in variations in the incidence angle and consequently leading to changes in the characteristics of the swept blade. Thus, a combination of simple functions and machine learning is utilized to model the circumferential fluctuation terms and quantify the sweep mechanism. The prediction accuracy of the model is high, with coefficient of determination greater than 0.95 on the test set. When the model is applied in a meridional flow analysis program, the calculation accuracy of the program for the incidence angle is improved by 0.4° and 0.6° at the design and off-design conditions respectively, compensating for the program's original deficiencies. Meanwhile, the model can also provide quantitative guidance for the design of swept blades, thereby reducing the number of design iterations and improving design efficiency.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 2","pages":"Pages 296-308"},"PeriodicalIF":5.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003692/pdfft?md5=1ee5c1e5d1e3ddffa49b9b47a16711be&pid=1-s2.0-S1000936123003692-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136128078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gust response of an elasto-flexible morphing wing using fluid–structure interaction simulations","authors":"Jonathan PFLÜGER,&nbsp;Christian BREITSAMTER","doi":"10.1016/j.cja.2023.12.017","DOIUrl":"10.1016/j.cja.2023.12.017","url":null,"abstract":"<div><p>Small and micro unmanned aircraft are the focus of scientific interest due to their wide range of applications. They often operate in a highly unstable flight environment where the application of new morphing wing technologies offers the opportunity to improve flight characteristics. The investigated concept comprises port and starboard adjustable wings, and an adaptive elasto-flexible membrane serves as the lifting surface. The focus is on the benefits of the deforming membrane during the impact of a one-minus-cosine type gust. At a low Reynolds number of <em>Re</em> = 264000, the morphing wing model is investigated numerically by unsteady fluid–structure interaction simulations. First, the numerical results are validated by experimental data from force and moment, flow field, and deformation measurements. Second, with the rigid wing as the baseline, the flexible case is investigated, focusing on the advantages of the elastic membrane. For all configurations studied, the maximum amplitude of the lift coefficient under gust load shows good agreement between the experimental and numerical results. During the decay of the gust, they differ more the higher the aspect ratio of the wing. When considering the flow field, the main differences are due to the separation behavior on the upper side of the wing. The flow reattaches earlier in the experiments than in the simulations, which explains the higher lift values observed in the former. Only at one intermediate configuration does the lift amplitude of the rigid configuration exceeds that of the flexible by about 12%, with the elastic membrane resulting in a smaller and more uniform peak load, which is also evident in the wing loading and hence in the root bending moment.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 2","pages":"Pages 45-57"},"PeriodicalIF":5.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123004326/pdfft?md5=273c582730d735ee5c05c85fa332fc18&pid=1-s2.0-S1000936123004326-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138987065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow characteristics of radial inflow in impeller rear cavity with baffle plate","authors":"Yang BAI ,&nbsp;Xiang LUO ,&nbsp;Dongdong LIU ,&nbsp;Zeyu WU ,&nbsp;Xiaoqiang ZHANG ,&nbsp;Sipeng WANG","doi":"10.1016/j.cja.2023.10.005","DOIUrl":"10.1016/j.cja.2023.10.005","url":null,"abstract":"<div><p>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 section. In this paper, a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle plate. The windage torque, flow structure and pressure drop between inlet and outlet were measured respectively. The experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33 × 10⁵ to 22.2 × 10⁵ and the range of mass flow rate coefficient was from 0.92 × 10⁴ to 2.92 × 10⁴. 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 cavity. Thus, the static pressure and total pressure drop in the rotor–stator cavity were reduced. The influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence parameters. Under large turbulence parameters, the windage torque would be reduced with baffle plate, while under small turbulence parameters, the baffle plate would increase with baffle plate. In general, the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 2","pages":"Pages 270-282"},"PeriodicalIF":5.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003497/pdfft?md5=91e9e21a6f932cd36376628dbad38654&pid=1-s2.0-S1000936123003497-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135706615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of stress distribution and damage behavior caused by forced installation of a composite bolted joint with a hole-location error","authors":"Chinan LIU ,&nbsp;Yuan LI ,&nbsp;Yi CHENG ,&nbsp;An'an ZHAO ,&nbsp;Kunpeng DU ,&nbsp;Yue SHI ,&nbsp;Ximing LI ,&nbsp;Hui CHENG","doi":"10.1016/j.cja.2023.07.038","DOIUrl":"10.1016/j.cja.2023.07.038","url":null,"abstract":"<div><p>In this paper, the influence of forced installation caused by a hole-location error on the 3D stress distribution and damage of a composite bolted joint is investigated. An analytical model of stress distributed on composite holes is promoted, in view of non-uniform extrusion caused by forced installation. At first, non-uniform extrusion of the hole edge caused by forced installation is analyzed. According to the contact state, expression of hole deformation is given. Then, based on Hertz theory, the maximum extrusion load is obtained with help of deformation expression. By constructing an elastic foundation beam model, 3D stress distributed on a hole could be analyzed according to the extrusion load. Then, stress distribution predicted by the above analytical method is compared with that provided by FE considering composite damage. Finally, a forced installation experiment is carried out to analyze the damage distribution of the joint. Results show that a central-symmetrically distributed stress is introduced by the hole-location error. With an increment of the error, strength of composite decreases due to extrusion damage. Therefore, stress presents a concave distribution on the hole. As the hole-location error exceeding 3%, stress decreases gradually due to failure of composite. Damage of holes does not exhibit a centrosymmetric distribution. Serious damage is mainly distributed on the entrance of the hole at the lower sheet.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Pages 201-217"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123002741/pdfft?md5=ff82a5f741108fb3ae4548c9bcdfba72&pid=1-s2.0-S1000936123002741-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48366473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial Board - Inside Front Cover","authors":"","doi":"10.1016/S1000-9361(23)00411-9","DOIUrl":"https://doi.org/10.1016/S1000-9361(23)00411-9","url":null,"abstract":"","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Page IFC"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123004119/pdfft?md5=7e24af15cfaa79ffc8fef8f08f375553&pid=1-s2.0-S1000936123004119-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139100919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A GMDA clustering algorithm based on evidential reasoning architecture","authors":"Haibin WANG ,&nbsp;Xin GUAN ,&nbsp;Xiao YI ,&nbsp;Shuangming LI ,&nbsp;Guidong SUN","doi":"10.1016/j.cja.2023.09.015","DOIUrl":"10.1016/j.cja.2023.09.015","url":null,"abstract":"<div><p>The traditional clustering algorithm is difficult to deal with the identification and division of uncertain objects distributed in the overlapping region, and aimed at solving this problem, the Evidential Clustering based on General Mixture Decomposition Algorithm (GMDA-EC) is proposed. First, the belief classification of target cluster is carried out, and the sample category of target distribution overlapping region is extended. Then, on the basis of General Mixture Decomposition Algorithm (GMDA) clustering, the fusion model of evidence credibility and evidence relative entropy is constructed to generate the basic probability assignment of the target and achieve the belief division of the target. Finally, the performance of the algorithm is verified by the synthetic dataset and the measured dataset. The experimental results show that the algorithm can reflect the uncertainty of target clustering results more comprehensively than the traditional probabilistic partition clustering algorithm.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Pages 300-311"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003199/pdfft?md5=e8a0e704817eca22d3e84d1b95b3ada4&pid=1-s2.0-S1000936123003199-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135389875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Air target intention recognition and causal effect analysis combining uncertainty information reasoning and potential outcome framework","authors":"Yu ZHANG,&nbsp;Fanghui HUANG,&nbsp;Xinyang DENG,&nbsp;Mingda LI,&nbsp;Wen JIANG","doi":"10.1016/j.cja.2023.09.008","DOIUrl":"10.1016/j.cja.2023.09.008","url":null,"abstract":"<div><p>Recognizing target intent is crucial for making decisions on the battlefield. However, the imperfect and ambiguous character of battlefield situations challenges the validity and causation analysis of classical intent recognition techniques. Facing with the challenge, a target intention causal analysis paradigm is proposed by combining with an Intervention Retrieval (IR) model and a Hybrid Intention Recognition (HIR) model. The target data acquired by the sensors are modelled as Basic Probability Assignments (BPAs) based on evidence theory to create uncertain datasets. Then, the HIR model is utilized to recognize intent for a tested sample from uncertain datasets. Finally, the intervention operator under the evidence structure is utilized to perform attribute intervention on the tested sample. Data retrieval is performed in the sample database based on the IR model to generate the intention distribution of the pseudo-intervention samples to analyze the causal effects of individual sample attributes. The simulation results demonstrate that our framework successfully identifies the target intention under the evidence structure and goes further to analyze the causal impact of sample attributes on the target intention.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Pages 287-299"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003126/pdfft?md5=e8e8d94b0f13b2ed45f439ef49674b00&pid=1-s2.0-S1000936123003126-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135299078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy evaluation for in-situ machining reference points binocular measurement based on credibility probability","authors":"Binchao YU ,&nbsp;Wei LIU ,&nbsp;Yanze ZHANG ,&nbsp;Dazhi MA ,&nbsp;Zhenyuan JIA ,&nbsp;Yi YUE ,&nbsp;Jiabo ZHANG","doi":"10.1016/j.cja.2023.04.007","DOIUrl":"10.1016/j.cja.2023.04.007","url":null,"abstract":"<div><p>Passive binocular measurement systems are being increasingly utilized in the in-situ industries of automobiles, aviation, and aerospace, etc. due to their excellent qualities of accuracy, efficiency, and cost performance. Whereas the barrier of evaluating the accuracy of measured objects resulted from the unequal equivalent focal length and quantization of pixels, has limited their further development and application of high requirements for in-situ machining, e.g., the measurement of machining reference points for the positioning of robotic drilling in aerospace manufacturing. In this paper, an accuracy evaluation method is proposed to address the problem. Firstly, the unequal equivalent focal length is considered to improve the accuracy of 3D reconstruction. Next, the credibility probability model is developed to calculate the probability of the observed error in the public view of the binocular measurement system and indicates the direction of improvement. Finally, the in-situ experiment is carried out to validate the method within the effective public view range of 300 mm × 300 mm. The experiment results show that the RMSs of observed errors are superior to 0.035 mm, and the credibility probabilities are all higher than 0.91; the maximum 3D reconstruction accuracy improvement is 60.3%, with the error reduced from 0.078 mm to 0.031 mm.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Pages 472-486"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S100093612300122X/pdfft?md5=f30609fadc377f8995a4d7c073e778fa&pid=1-s2.0-S100093612300122X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42442185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elaborative collection of condensed combustion products of solid propellants: Towards a real Solid Rocket Motor (SRM) operational environment","authors":"Wenchao ZHANG ,&nbsp;Zhimin FAN ,&nbsp;Dongliang GOU ,&nbsp;Yao SHU ,&nbsp;Peijin LIU ,&nbsp;Aimin PANG ,&nbsp;Wen AO","doi":"10.1016/j.cja.2023.09.006","DOIUrl":"10.1016/j.cja.2023.09.006","url":null,"abstract":"<div><p>A novel constant-pressure and constant-quenching distance Condensed Combustion Products (CCPs) collection system was developed, coupled with a timing control system, to collect the CCPs formed in the course of burning of aluminum-based composite propellants. The effects of adiabatic graphite plating, collection zone, quenching distance, time series of collection, and propellant burning rate on the microscopic morphology, particle size distribution and unburned aluminum content of CCPs were investigated. It was verified that the graphite plating can provide a high-fidelity high-temperature environment for propellant combustion. The combustion efficiency is improved by 2.44% compared to the bare propellant case. The time series of collection has a significant effect on the combustion efficiency of aluminum, and the combustion efficiency of aluminum in the thermal state (1.2–2.4 s) is 2.75% higher than that in the cold state (0–1.2 s). Similarly, the characteristics of the CCPs in different collection zones are different. At the quenching distance of 5 mm, the combustion efficiency of aluminum in the core zone (85.39%) is much lower than that in the outer zone (92.07%), while the particle size of the CCPs in the core zone (172 μm) is larger than that in the outer zone (41 μm). This indicates that the core zone is more likely to produce large-sized and incompletely burned agglomerates during the propellant combustion process. Different burning rates also lead to a significant difference in particle size distribution and combustion efficiency. High burning rates result in higher combustion efficiency. A detailed sequence of the elaborative collection process of CCPs is proposed, mainly including the setting of ignition delay time, burning rate, working pressure, plating length and time series of collection. The findings of this study are expected to provide a reliable tool for the evaluation of the combustion efficiency of solid propellants.</p></div>","PeriodicalId":55631,"journal":{"name":"Chinese Journal of Aeronautics","volume":"37 1","pages":"Pages 77-88"},"PeriodicalIF":5.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1000936123003102/pdfft?md5=ebb0b320066070203724991cc336448a&pid=1-s2.0-S1000936123003102-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135249335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}