Linlin Zhang, Lvzhao Bai, Jianshu Liang, Zhiying Qin^*, Yuejing Zhao

Computer Systems Science and Engineering, Vol.48, No.6, pp. 1557-1579, 2024, DOI:10.32604/csse.2024.054237 - 22 November 2024

Abstract Quadrotor unmanned aerial vehicles (UAVs) are widely used in inspection, agriculture, express delivery, and other fields owing to their low cost and high flexibility. However, the current UAV control system has shortcomings such as poor control accuracy and weak anti-interference ability to a certain extent. To address the control problem of a four-rotor UAV, we propose a method to enhance the controller’s accuracy by considering underactuated dynamics, nonlinearities, and external disturbances. A mathematical model is constructed based on the flight principles of the quadrotor UAV. We develop a control algorithm that combines humanoid intelligence with… More >

Chunxiu Ji¹, Dan Xie^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.30, No.2, pp. 1-1, 2024, DOI:10.32604/icces.2024.012592

Abstract The persistence of accidents attributed to structural damage in traditional rotor blades remains a pressing concern for aeronautical experts. Given the infrequency of flutter in undamaged blades, this study directs its attention to a rotor blade afflicted with structural damage, with a primary objective of discerning flutter occurrences, elucidating underlying mechanisms, and scrutinizing resultant aeroelastic responses. This paper presents an investigation into the flutter mechanism observed in transonic rotor blades subjected to structural damage, employing the Spectral Proper Orthogonal Decomposition(SPOD) method. The study aims to understand the dynamics of flutter under the influence of structural More >

Zhuo Liu, Yecui Yan^*

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1443-1460, 2024, DOI:10.32604/fhmt.2024.056091 - 30 October 2024

Abstract The external rotor hub motor adopts direct drive mode, no deceleration drive device, and has a compact structure. Its axial size is smaller than that of a deceleration-driven hub motor, which greatly reduces the weight of the vehicle and increases the cruising range of the vehicle. Because of the limited special working environment and performance requirements, the hub motor has a small internal space and a large heat generation, so it puts forward higher requirements for heat dissipation capacity. For the external rotor hub motor, a new type of in-tank water-cooled structure of hub motor… More >

Abdellatif El Hannaoui^1,*, Rachid Boutarfa¹, Chadia Haidar²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 733-746, 2024, DOI:10.32604/fhmt.2024.050520 - 11 July 2024

Abstract The proposed work focuses on the in-depth study of convective heat transfer in the unconfined air gap of a discoidal rotor-stator system. The rotary cooling mechanism is achieved by the injection of two air jets, while the cavity geometry is characterized by a dimensionless parameter G. The numerical analysis primarily concentrated on the effect of flow velocity and rotation on the heat exchange process. More precisely, the range of analysis extends from the rotational Reynolds number to , while varying the Reynolds value of the jet in a range from to . To carry out More >

Mengdong An¹, Weiyuan Zhong¹, Wei Xu², Xiuli Wang^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1331-1349, 2024, DOI:10.32604/fdmp.2023.046604 - 27 June 2024

Abstract The reactor coolant pump (RCP) rotor seizure accident is defined as a short-time seizure of the RCP rotor. This event typically leads to an abrupt flow decrease in the corresponding loop and an ensuing reactor and turbine trip. The significant reduction of core coolant flow while the reactor is being operated at full load can have very negative consequences. This potentially dangerous event is typically characterized by a complex transient behavior in terms of flow conditions and energy transformation, which need to be analyzed and understood. This study constructed transient flow and rotational speed mathematical More > Graphic Abstract

Cheng-Yeh Li, Jui-Hsiang Kao^*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2277-2304, 2024, DOI:10.32604/cmes.2023.030215 - 15 December 2023

Abstract The performance of a water jet propulsion system is related to the inlet duct, rotor, stator, and nozzle. Generally, the flow inlet design must fit the bottom line of the hull, and the design of the inlet duct is often limited by stern space. The entire section, from the rotor to the nozzle through the stator, must be designed based on system integration in that the individual performance of these three components will influence each other. Particularly, the section from the rotor to the nozzle significantly impacts the performance of a water jet propulsion system.… More >

Chunxiu Ji¹, Dan Xie^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010329

Abstract Blade flutter is a complex phenomenon that can lead to serious damage or failure of turbomachinery systems. Predicting and mitigating blade flutter is therefore an important aspect of the design and analysis of these systems[1]. In this paper, we present a comparative study of two representative methods for blade flutter predictions: the energy method and the computational fluid dynamics/computational structural dynamics (CFD/CSD) coupled time-domain method. The energy method is a decoupled approach that uses a simplified model of the blade and fluid-structure interaction to calculate the stability boundaries of the system[2]. The time-domain method, on… More >

Zhaolin Chen^1,*, Xiaohui Wei¹, Tianhang Xiao¹, Ning Qin²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09976

Abstract A computational study has been conducted on various airfoils to simulate flows at low Reynolds numbers 17,000 and 21,000 with Mach number changes from 0.25 to 0.85 to provide understanding and guidance for Mars rotory wing designs. The computational fluid dynamics tool used in this study is a Reynolds-averaged Navier–Stokes solver with a transition model (k-ω SST γ-Reθ). The airfoils investigated in this study include NACA airfoils (4, 5, and 6% camber), UltraThin airfoils, and thin cambered plates (3% camber, but various maximum camber locations). Airfoils were examined for lift and drag performance as well… More >

Gang Liu¹, Xinqi Chen^2,3,*, Lijuan Bao¹, Linbo Xu^2,3, Chaochao Dai¹, Lei Yang^2,3, Chengmin Wang⁴

Structural Durability & Health Monitoring, Vol.17, No.4, pp. 337-351, 2023, DOI:10.32604/sdhm.2022.023583 - 02 August 2023

Abstract Aiming at the fact that the rotor winding inter-turn weak faults can hardly be detected due to the strong electromagnetic coupling effect in the excitation system, an interval observer based on current residual is designed. Firstly, the mechanism of the inter-turn short circuit of the rotor winding in the excitation system is modeled under the premise of stable working conditions, and electromagnetic decoupling and system simplification are carried out through Park Transform. An interval observer is designed based on the current residual in the two-phase coordinate system, and the sensitive and stable conditions of the… More >

Youping Lin¹, Huangbin Lin^2,*, Dezhi Wei¹

Intelligent Automation & Soft Computing, Vol.37, No.2, pp. 1363-1379, 2023, DOI:10.32604/iasc.2023.038601 - 21 June 2023

Abstract The digital twin (DT) includes real-time data analytics based on the actual product or manufacturing processing parameters. Data from digital twins can predict asset maintenance requirements ahead of time. This saves money by decreasing operating expenses and asset downtime, which improves company efficiency. In this paper, a digital twin in braiding machinery based on IoT (DTBM-IoT) used to diagnose faults. When an imbalance fault occurs, the system gathers experimental data. After that, the information is sent into a digital win model of the rotor system to see whether it can quantify and locate imbalance for More >