Article
Mechanics
Xu Wang, Jiaqing Kou, Weiwei Zhang
Summary: Ice accretion on wind turbine blades and wings can negatively impact their aerodynamic performance, but predicting the unsteady performance under icing conditions is challenging. This study proposes a multi-fidelity reduced-order model based on multi-task learning to efficiently predict the aerodynamic performance. The model achieves better accuracy and can be generalized to different ice shapes, improving the efficiency of unsteady prediction.
Article
Engineering, Aerospace
Vishal Raul, Leifur Leifsson
Summary: The dynamic stall phenomenon is characterized by the formation of a leading-edge vortex, which impacts the structural strength and life of a system. Aerodynamic shape optimization provides a cost-effective method to delay or mitigate these characteristics, but it requires time-consuming CFD simulations. A surrogate-based optimization technique is proposed in this work to reduce the computational cost of ASO for airfoil dynamic stall characteristics.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
Jinhua Lou, Rongqian Chen, Jiaqi Liu, Yue Bao, Yancheng You, Zhengwu Chen
Summary: This paper proposes a method for the aerodynamic optimization of airfoils based on a combination of deep learning and reinforcement learning. The results show that the proposed method can improve the lift-drag ratio of the airfoil to 71.46%.
Article
Engineering, Aerospace
Liu Liu, Tianqi Wang, Zeming Gao, Lifang Zeng, Xueming Shao
Summary: This study proposes an optimization framework based on deep learning and multi-island genetic algorithm to obtain the optimal leading edge shape of ducted propellers in eVTOL. By using a modified shape parameterization method and establishing a deep learning surrogate model, high precision and efficiency in optimization are achieved.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Aerospace
Xiaojing Wu, Zijun Zuo, Long Ma
Summary: The study introduces a novel data-driven surrogate-assisted teaching-learning-based optimization framework for constrained aerodynamic shape optimization, aiming to promote ASO using historical aerodynamic process data and relieve manual design experience through nonparametric adjustment of the TLBO algorithm.
Article
Engineering, Aerospace
Caterina Poggi, Monica Rossetti, Giovanni Bernardini, Umberto Iemma, Cristiano Andolfi, Christian Milano, Massimo Gennaretti
Summary: This paper discusses the development of innovative surrogate models suitable for multi-propeller systems, such as those used in urban air-mobility vehicles. It focuses on the simulation of aerodynamic performance and acoustic emission using two modelling techniques: Artificial Neural Networks and Genetic Programming. The numerical investigation demonstrates that both metamodelling techniques can accurately reproduce propeller aerodynamic performance and radiated noise, making them suitable for preliminary design applications.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Feng Deng, Cheng Xue, Ning Qin
Summary: A novel shape parameterization method for airfoil design is proposed, which provides design variables related to aerodynamic characteristics based on linearized aerodynamic theory. The method offers more useful aerodynamic performance parameters.
Article
Computer Science, Interdisciplinary Applications
Wei Zhang, Zhenghong Gao, Chao Wang, Lu Xia
Summary: This paper introduces an optimization strategy based on a niching-based adaptive space reconstruction method for the aerodynamic, geometric, and stealth performance of flying wing aircraft. The proposed method uses a multiple points sampling approach to search for local minima and reduces computational cost by focusing on less-explored minima.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Mechanics
Qiuwan Du, Tianyuan Liu, Like Yang, Liangliang Li, Di Zhang, Yonghui Xie
Summary: In this paper, a convolutional neural network framework is established based on the deep learning method for airfoil design optimization and performance prediction. The experimental results show that the framework has significant advantages such as good robustness, great convergence, fast computation speed, and high prediction accuracy.
Article
Mechanics
Pengyao Gong, Emmanuvel Joseph Aju, Yaqing Jin
Summary: The aerodynamic performances and flow statistics of a Delft University-91-W2-250 airfoil with deformable vortex generators (DVG) were experimentally investigated. The results showed that DVG could effectively enhance lift coefficient for the airfoil with clean surface under low incoming winds. However, the deformation of DVGs increased with wind speed, leading to reduced effectiveness of wake mixing and gradually approaching the performance of clean surface configuration.
Article
Engineering, Aerospace
Tao Zhang, George N. Barakos, Furqan, Malcolm Foster
Summary: This paper presents a multi-fidelity propeller design and analysis process, which is demonstrated for the preliminary design of the Skybus eVTOL vehicle. The framework integrates tools and results of variable fidelity levels, starting with a low-fidelity global scan and progressing to high-fidelity CFD simulations and optimisation. The method is validated and applied to the propeller design of the Skybus vehicle.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Multidisciplinary
Kai Wang, Zhong-Hua Han, Ke-Shi Zhang, Wen-Ping Song
Summary: Handling a large number of geometric constraints poses a significant challenge for surrogate-based aerodynamic shape optimization (ASO) driven by computational fluid dynamics (CFD). This article proposes an efficient method that uses the Kreisselmeier-Steinhauser (KS) method to aggregate all geometric constraints into one that can be approximated by a cheap surrogate model, improving the optimization efficiency of ASO. Results show that the proposed method has the potential to handle a larger number and more types of geometric constraints, offering great potential for enhancing the optimization process.
ENGINEERING APPLICATIONS OF COMPUTATIONAL FLUID MECHANICS
(2023)
Article
Engineering, Marine
Jian Hu, Tao Li, Jueru Wang, Weipeng Zhang, Chunyu Guo
Summary: This paper investigates the hydrodynamics and vortex shedding of cycloidal blades through numerical simulations, which show good agreement with experimental results. Parametric analysis reveals that eccentricity, advance coefficient, and position of rotation center have significant effects on vortex formation and shedding.
JOURNAL OF MARINE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Marine
Tao Li, Shili Sun
Summary: Computational fluid dynamics (CFD) simulations were used to investigate the scale effect on the hydrodynamic performance of a single-blade cycloidal propeller. The study determined the hydrodynamic coefficients using the Shear Stress Transport (SST) turbulence model and a reasonable numerical scheme. The results showed that the scale effect of the cycloidal propeller differs from conventional screw propellers, leading to the invalidation of the scale effect formula recommended by the International Towing Tank Conference (ITTC). A new formula based on extensive numerical simulations was proposed.
Article
Engineering, Aerospace
Bei Liu, Hua Liang, Zhong-Hua Han, Guang Yang
Summary: This article proposes a new morphing mechanism for aerodynamic shape design considering both subsonic and hypersonic performance. The optimization design utilizes a surrogate-based optimization algorithm and considers multiple configurations and flow conditions. The results show that the optimized morphing wing exhibits significant aerodynamic performance improvement across different flow regimes.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Wei-Cheng Xie, Xiao-Liang Wang, Deng-Ping Duan, Ji-Wei Tang
Article
Mechanics
Wei Cheng Xie, Xiao Liang Wang, Deng Ping Duan, Ji Wei Tang
JOURNAL OF MECHANICS
(2020)
Article
Engineering, Aerospace
W-C Xie, X-L Wang, D-P Duan, J-W Tang, Y. Wei
Summary: This study investigates the stress-strain characteristics of flexible airship materials, utilizing biaxial tensile testing and Digital Image Correlation technology to draw conclusions on the mechanical properties of the materials. The findings play a significant role in the design of flexible airship envelopes.
AERONAUTICAL JOURNAL
(2021)
Article
Automation & Control Systems
Yan Wei, Pingfang Zhou, Yueying Wang, Dengping Duan, Jiwei Tang
Summary: This paper investigates finite-time tracking control for multiple-input-multiple-output nonlinear systems with uncertainties and full state constraints. It introduces integral barrier Lyapunov functionals (iBLF) and an adaptive finite-time neural control scheme, as well as a new finite-time convergent differentiator to address complexity issues in traditional backstepping control designs. Stability analysis shows that all closed-loop signals are semi-globally uniformly ultimately bounded, ensuring finite-time convergence and non-violation of state constraints. Simulation results for attitude tracking on an autonomous airship validate the effectiveness of the proposed scheme.
TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL
(2021)
Article
Automation & Control Systems
Yan Wei, Pingfang Zhou, Weicheng Xie, Jiwei Tang, Dengping Duan
Summary: This paper presents an event-triggered adaptive output-feedback control approach for MIMO uncertain nonlinear systems, with the use of a nonlinear mapping function and neural networks for compensation. A state observer is established to estimate unmeasured states, and an event-triggering rule is applied to determine the timing of control transmission, ensuring both control effectiveness and constraint satisfaction.
ASIAN JOURNAL OF CONTROL
(2022)
Article
Automation & Control Systems
Peng Zhang, Quanbao Wang, Jiwei Tang, Dengping Duan
Summary: This article proposes an agent-based cooperative control method for high order dynamic nonlinear stratosphere airships in an earth-observing system. Distributed control is designed to achieve leader-following consensus in the stratosphere airship earth-observing system. Numerical results are presented to demonstrate the effectiveness of the proposed leader-following scheme.
INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL
(2022)
Article
Engineering, Multidisciplinary
Peng Zhang, Quanbao Wang, Yueying Wang, Jiwei Tang, Dengping Duan
Summary: This technical note investigates the agent-based finite-time leader-following consensus for Earth-observation systems with multiple stratosphere airships. The study considers the high-order nonlinear dynamic and external disturbances in multi-agent systems. By using a distributed observer to acquire the state of the leader airship, a dynamic cascade control is designed to achieve finite-time leader-following consensus for Earth-observation systems. Mathematical proofs demonstrate the finite convergence of the stratosphere airship earth-observation system, and simulation results confirm the effectiveness of the proposed scheme.
IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Aerospace
Weicheng Xie, Xiaoliang Wang, Jiwei Tang, Yonglin Chen, Junjie Wu
Summary: In this study, a temperature control device suitable for biaxial tension was designed, and the biaxial tension test of the UN-5100 material in high and low-temperature environments was realized. The test results showed that the elastic modulus and Poisson's ratio of the airship envelope were larger at low temperatures, indicating that the capsule is relatively safe at such temperatures.
Article
Engineering, Aerospace
Jiwei Tang, Shilong Bai, Weicheng Xie, Junjie Wu, Hanjie Jiang, Yuxuan Sun
Summary: The research focuses on the stratospheric airship and carries out motion mode analysis. Key parameters such as the center of mass, the center of buoyance, and the aerodynamic stability moment are analyzed and summarized for their influence on the motion mode of the stratospheric airship. Unlike high-speed and high-dynamic aircraft, aerodynamic stability moment does not significantly affect the motion modes of the stratospheric airship. Perturbations to the vertical center of mass and buoyancy have a significant impact on the pitch pendulum motion modes, affecting their frequency and stability.
Article
Engineering, Aerospace
Jiwei Tang, Weicheng Xie, Pingfang Zhou, Hui Yang, Tongxin Zhang, Quanbao Wang
Summary: This paper presents a multidisciplinary approach to design and optimize a solar-powered stratospheric airship. The methodology takes into account various factors from different disciplines and uses a numerical method to calculate the solar power output in the optimization process. Results show that the methodology can achieve a 19.2% reduction in airship volume compared to arbitrary initial parameters, highlighting the importance of solar array layouts and circumferential location.
Article
Engineering, Aerospace
Jiwei Tang, Weicheng Xie, Xiaoliang Wang, Yonglin Chen, Junjie Wu
Summary: An optimal calculation method for the mechanical properties of near-space capsule materials was proposed in this study. Through biaxial tensile tests and finite element simulation, the elastic modulus and Poisson's ratio of near-space capsule materials can be accurately predicted, which is adaptable to engineering applications.
Article
Engineering, Aerospace
Yuhao Jing, Yang Wu, Jiwei Tang, Pingfang Zhou, Dengping Duan
Summary: The paper proposes a new trajectory generation method for the return phase of stratospheric airships. By considering energy consumption and wind field, the article constructs optimization objectives and conditions for the return trajectory. The modified interior point method and adaptive gradient descent regulator are used to improve efficiency and stability of the optimization process.
Article
Engineering, Aerospace
Jiwei Tang, Shumin Pu, Peixi Yu, Weicheng Xie, Yunfei Li, Binxing Hu
Summary: This study establishes a comprehensive simulation model to predict the trajectory of a high-altitude zero-pressure balloon flight system. The effects of control strategy on flight performance are investigated, and the results show that the vertical landing speed of the system can approach zero with the applied control strategy.
Article
Engineering, Aerospace
Jiwei Tang, Weicheng Xie, Xiaoliang Wang, Cheng Chen
Summary: This study establishes a mechanical properties calculation model for near-space airship envelope materials, taking into account the effects of stress ratios, stress magnitudes, and temperatures. By using various simulation and analysis techniques, the fluid-structure-thermal coupling model of airship envelopes is developed, allowing for a more accurate prediction of stress-strain distribution and deformation characteristics.
Article
Engineering, Aerospace
Jiwei Tang, Dengping Duan, Weicheng Xie
Summary: This paper presents a shape exploration and multidisciplinary optimization method for unconventional semirigid nearing space airships, utilizing improved disciplines interaction. The approach allows for direct optimization of general configurations and subsystem parameters. The results show increased payload capacity and sensitivity of the airship's volume to specific parameters.
JOURNAL OF AIRCRAFT
(2022)