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  • Open Access


    Hybrid Energy Storage to Control and Optimize Electric Propulsion Systems

    Sikander Hans1, Smarajit Ghosh1, Suman Bhullar1, Aman Kataria2, Vinod Karar2,*, Divya Agrawal2

    CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 6183-6200, 2022, DOI:10.32604/cmc.2022.020768

    Abstract Today, ship development has concentrated on electrifying ships in commercial and military applications to improve efficiency, support high-power missile systems and reduce emissions. However, the electric propulsion of the shipboard system experiences torque fluctuation, thrust, and power due to the rotation of the propeller shaft and the motion of waves. In order to meet these challenges, a new solution is needed. This paper explores hybrid energy management systems using the battery and ultracapacitor to control and optimize the electric propulsion system. The battery type and ultracapacitor are ZEBRA and MAXWELL, respectively. The 3-, 4-and 5-blade propellers are considered to produce… More >

  • Open Access


    FCS-MPC Strategy for PV Grid-Connected Inverter Based on MLD Model

    Xiaojuan Lu, Qingbo Zhang*

    Energy Engineering, Vol.118, No.6, pp. 1729-1740, 2021, DOI:10.32604/EE.2021.014938

    Abstract In the process of grid-connected photovoltaic power generation, there are high requirements for the quality of the power that the inverter breaks into the grid. In this work, to improve the power quality of the grid-connected inverter into the grid, and the output of the system can meet the grid-connected requirements more quickly and accurately, we exhibit an approach toward establishing a mixed logical dynamical (MLD) model where logic variables were introduced to switch dynamics of the single-phase photovoltaic inverters. Besides, based on the model, our recent efforts in studying the finite control set model predictive control (FCS-MPC) and devising… More >

  • Open Access


    A Review of the Dynamic Modeling Approaches for Characterizing Fluid Flow in Naturally Fractured Reservoirs

    M. N. Tarhuni*, W. R. Sulaiman, M. Z. Jaafar, M. Milad, A. M. Alghol

    Energy Engineering, Vol.118, No.4, pp. 761-795, 2021, DOI:10.32604/EE.2021.016645

    Abstract Fluid flow in fractured media has been studied for decades and received considerable attention in the oil and gas industry because of the high productivity of naturally fractured reservoirs. Due to formation complexity and reservoir heterogeneity, characterizing fluid flow with an appropriate reservoir model presents a challenging task that differs relatively from homogeneous conventional reservoirs in many aspects of view, including geological, petrophysical, production, and economics. In most fractured reservoirs, fracture networks create complex pathways that affect hydrocarbon flow, well performance, hence reservoir characterization. A better and comprehensive understanding of the available reservoir modeling approaches is much needed to accurately… More >

  • Open Access


    Peridynamic Modeling and Simulation of Fracture Process in Fiber-Reinforced Concrete

    Zhuang Chen1, Xihua Chu1,2,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.1, pp. 241-272, 2021, DOI:10.32604/cmes.2021.015120

    Abstract In this study, a peridynamic fiber-reinforced concrete model is developed based on the bond-based peridynamic model with rotation effect (BBPDR). The fibers are modelled by a semi-discrete method and distributed with random locations and angles in the concrete specimen, since the fiber content is low, and its scale is smaller than the concrete matrix. The interactions between fibers and concrete matrix are investigated by the improvement of the bond’s strength and stiffness. Also, the frictional effect between the fibers and the concrete matrix is considered, which is divided into static friction and slip friction. To validate the proposed model, several… More >

  • Open Access


    Dynamic Modeling of the Feed Drive System of a CNC Metal Cutting Machine

    H. Heydarnia1,*, I. A. Kiselev1, M. M. Ermolaev2, S. Nikolaev3

    Sound & Vibration, Vol.55, No.1, pp. 19-30, 2021, DOI:10.32604/sv.2021.04410

    Abstract Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control (CNC) machines. The preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational conditions. Rotational acceleration of the screw also affects the performance of the CNC feed drive when machining small parts. This paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able to eliminate an observed resonance… More >

  • Open Access


    A Rate-Dependent Peridynamic Model for the Dynamic Behavior of Ceramic Materials

    Bufan Chu1,2, Qiwen Liu1,2, Lisheng Liu1,2,3,*, Xin Lai1,2, Hai Mei1,2

    CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 151-178, 2020, DOI:10.32604/cmes.2020.010115

    Abstract In this study, a new bond-based peridynamic model is proposed to describe the dynamic properties of ceramics under impact loading. Ceramic materials show pseudo-plastic behavior under certain compressive loadings with high strain-rate, while the characteristic brittleness of the material dominates when it is subjected to tensile loading. In this model, brittle response under tension, softening plasticity under compression and strain-rate effect of ceramics are considered, which makes it possible to accurately capture the overall dynamic process of ceramics. This enables the investigation of the fracture mechanism for ceramic materials, during ballistic impact, in more detail. Furthermore, a bond-force updating algorithm… More >

  • Open Access


    A Patient-Specific Computational Fluid Dynamic Model of Middle Cerebral Artery Aneurysm Before and One Year After Surgery

    Shicheng He1, Juhui Qiu1, Wanling Liu1, Tieying Yin1, Dechuan Zhang2,*, Donghua Liao3,4, Haijun Zhang5, Yuxia Yin5, Guixue Wang1,*

    Molecular & Cellular Biomechanics, Vol.17, No.2, pp. 63-74, 2020, DOI:10.32604/mcb.2020.08750

    Abstract Computational fluid dynamics (CFD) has been widely used for studying intracranial aneurysm hemodynamics, while its use for guiding clinical strategy is still in development. In this study, CFD simulations helped inform treatment decision for a middle cerebral artery (MCA) aneurysm case was investigated. A patient with a 10.4 × 9.8 mm aneurysm attached with a small aneurysm at the edge of the trifurcation in the left MCA was included in this study. For removing the MCA aneurysm, two scenarios were considered: Plan-A involved clipping the small aneurysm and Plan-B involved clipping the whole aneurysm. A suitable treatment plan was decided… More >

  • Open Access


    Sliding-Mode PID Control of UAV Based on Particle Swarm Parameter Tuning

    Yunping Liu1, 2, *, Xingxing Yan1, Fei Yan1, Ze Xu1, Weiyan Shang3

    CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 469-487, 2020, DOI:10.32604/cmc.2020.05746

    Abstract Due to the coupled motion between the rotor unmanned aerial vehicle (UAV) and the manipulator, the underactuation characteristics of the system itself, and the influence of external uncertainties, the stability of the rotor UAV’s manipulator control system is difficult to control. Based on the dynamic model of the rotor UAV, the stability of the whole UAV manipulator control system is improved by using the piecewise cost function, the compression factor particle swarm optimization (PSO) algorithm and the sliding mode PID to establish the sliding mode PID control stability method based on the PSO. Compared with the sliding mode PID control… More >

  • Open Access


    Peridynamic Modeling and Simulation of Ice Craters By Impact

    Ying Song1,2, Jiale Yan1,2, Shaofan Li2,*, Zhuang Kang1

    CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 465-492, 2019, DOI:10.32604/cmes.2019.07190

    Abstract In the present work, a state-based peridynamics with adaptive particle refinement is proposed to simulate water ice crater formation due to impact loads. A modified Drucker-Prager constitutive model was adopted to model ice and was implemented in the state-based peridynamic equations to analyze the elastic-plastic deformation of ice. In simulations, we use the fracture toughness failure criterion in peridynamics to simulate the quasi-brittle failure of ice. An adaptive particle refinement method in peridynamics was proposed to improve computational efficiency. The results obtained using the peridynamic model were compared with the experiments in previous literatures. It was found that the peridynamic… More >

  • Open Access


    Dynamic Fracture Analysis of Functionally Gradient Materials with Two Cracks By Peridynamic Modeling

    Zhanqi Cheng1, Dongdong Jin1, Chengfang Yuan1, Le Li1,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 445-464, 2019, DOI:10.32604/cmes.2019.06374

    Abstract In the research, the dynamic fracture failure problem of functionally graded materials (FGMs) containing two pre-cracks was analyzed using a bond-based Peridynamic (PD) method numerical model. The two convergence of decreasing the area of PD horizon (δ-convergence) and uniform mesh refinement (m-convergence) were studied. The effects of both crack position and distance between two cracks on crack propagation pattern in FGMs plate under tensile loads are studied. Furthermore, the effects of different gradient patterns on the dynamic propagation of cracks in FGMs are also investigated. The simulate results suggest that the cracks positions and the distance between them can significantly… More >

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