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  • Open Access

    ARTICLE

    Decoupling Algorithms for the Gravitational Wave Spacecraft

    Xue Wang1,2, Weizhou Zhu1,2, Zhao Cui2,3, Xingguang Qian2,3, Jinke Yang1,2, Jianjun Jia1,2,*, Yikun Wang2,3,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 325-337, 2024, DOI:10.32604/cmes.2024.048804

    Abstract The gravitational wave spacecraft is a complex multi-input multi-output dynamic system. The gravitational wave detection mission requires the spacecraft to achieve single spacecraft with two laser links and high-precision control. Establishing one spacecraft with two laser links, compared to one spacecraft with a single laser link, requires an upgraded decoupling algorithm for the link establishment. The decoupling algorithm we designed reassigns the degrees of freedom and forces in the control loop to ensure sufficient degrees of freedom for optical axis control. In addressing the distinct dynamic characteristics of different degrees of freedom, a transfer function compensation method is used in… More >

  • Open Access

    ARTICLE

    Dynamic Response of Foundations during Startup of High-Frequency Tunnel Equipment

    Dawei Ruan1, Mingwei Hu1,2,3,4,5,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 821-844, 2024, DOI:10.32604/cmes.2024.048392

    Abstract The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale, multifunctional, and complex orientations. The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units, and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts, leading to variations in the dynamic response of the foundation. The high-frequency units yield significantly diverse outcomes under different startup conditions and times, resulting in failure to meet operational requirements, influencing the normal function of the tunnel, and causing harm to the foundation structure, personnel, and property in severe cases. This article… More >

  • Open Access

    ARTICLE

    Multi-Stage Multidisciplinary Design Optimization Method for Enhancing Complete Artillery Internal Ballistic Firing Performance

    Jipeng Xie1,2, Guolai Yang1,*, Liqun Wang1, Lei Li1

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 793-819, 2024, DOI:10.32604/cmes.2024.048174

    Abstract To enhance the comprehensive performance of artillery internal ballistics—encompassing power, accuracy, and service life—this study proposed a multi-stage multidisciplinary design optimization (MS-MDO) method. First, the comprehensive artillery internal ballistic dynamics (AIBD) model, based on propellant combustion, rotation band engraving, projectile axial motion, and rifling wear models, was established and validated. This model was systematically decomposed into subsystems from a system engineering perspective. The study then detailed the MS-MDO methodology, which included Stage I (MDO stage) employing an improved collaborative optimization method for consistent design variables, and Stage II (Performance Optimization) focusing on the independent optimization of local design variables and… More >

  • Open Access

    ARTICLE

    Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

    Zun-Di Huang1, Zhen-Bin Zhou1,2,3, Ning Chang1, Zheng-Wei Chen2,3,*, Su-Mei Wang2,3,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 975-996, 2024, DOI:10.32604/cmes.2024.047664

    Abstract The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics. Therefore, this paper uses an improved delayed detached eddy simulation (IDDES) method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds. The effects of marshaling lengths (varying from 3-car to 8-car groups) on the train’s aerodynamic performance, surface pressure, and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes (N-S) equations. The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle… More > Graphic Abstract

    Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

  • Open Access

    ARTICLE

    A Coupled Thermomechanical Crack Propagation Behavior of Brittle Materials by Peridynamic Differential Operator

    Tianyi Li1,2, Xin Gu2, Qing Zhang2,*

    CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 339-361, 2024, DOI:10.32604/cmes.2024.047566

    Abstract This study proposes a comprehensive, coupled thermomechanical model that replaces local spatial derivatives in classical differential thermomechanical equations with nonlocal integral forms derived from the peridynamic differential operator (PDDO), eliminating the need for calibration procedures. The model employs a multi-rate explicit time integration scheme to handle varying time scales in multi-physics systems. Through simulations conducted on granite and ceramic materials, this model demonstrates its effectiveness. It successfully simulates thermal damage behavior in granite arising from incompatible mineral expansion and accurately calculates thermal crack propagation in ceramic slabs during quenching. To account for material heterogeneity, the model utilizes the Shuffle algorithm… More >

  • Open Access

    ARTICLE

    Spatio-Temporal Dynamics of Land Use in Cotton and Cereal Production Zones, Mali

    Dynamiques Spatio-Temporelles de l’Occupation des Terres dans les Zones de Production Cotonnière et Céréalière au Mali

    Moumouni Sidibé1,2,*, Augustin K. N. Aoudji1, Yaya Issifou Moumouni3,*, Issa Sacko4, Idelphonse Saliou1, Bourema Koné2, Achille Ephrem Assogbadjo5, Afio Zannou1

    Revue Internationale de Géomatique, Vol.33, pp. 51-76, 2024, DOI:10.32604/rig.2024.045505

    Abstract Land use dynamics is a prerequisite for identifying natural resource management constraints, the evolution of agrarian practices and population growth. The objective of this research is to improve knowledge of the dynamics of agricultural land use in the dryland (Cinzana) and cotton (Kléla) areas of Mali. The methodology used consisted of planimetric data collection and diachronic analysis using Landsat TM (Thematic Mapper) satellite images from 2000 and OLI (Operational Land Image) from 2020. Degradation and deforestation rates of natural formations were calculated on the one hand, and on the other hand, the speed and intensity of changes were evaluated using… More > Graphic Abstract

    Spatio-Temporal Dynamics of Land Use in Cotton and Cereal Production Zones, Mali<br/><br/>Dynamiques Spatio-Temporelles de l’Occupation des Terres dans les Zones de Production Cotonnière et Céréalière au Mali

  • Open Access

    ARTICLE

    Swelling dynamics of Poly (N, N- Dimethylacrylamide - co- Crotonic acid) Hydrogel and Evaluation of its Potential for Controlled Release of Fertilizers

    FATMA LOUZRI, SADJIA BENNOUR

    Journal of Polymer Materials, Vol.37, No.1-2, pp. 55-76, 2020, DOI:10.32381/JPM.2020.37.1-2.5

    Abstract Poly(N,N-dimethymethylacrylamide -co-crotonic acid) (P(DMA-CAx)) hydrogels were prepared by free radical polymerization, using N,N- methylenebisacrylamide (NMBA) as cross-linking agent. The synthesized hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The effects of comonomer composition and pH of the medium on the swelling behavior of hydrogels were investigated. The obtained results showed that the swelling capabilities of hydrogels increased as crotonic acid content and pH increased. In order to evaluate the controlled release potential of the polymeric matrix, it was loaded with potassium nitrate and ammonium nitrate as fertilizers and the release kinetics was studied as a… More >

  • Open Access

    ARTICLE

    On the Engineering Properties of TPV derived from Hypalon, PP and a Compatibilizer (PMES-MA) prepared by Dynamic Vulcanization

    ASIS K. MANDAL1, DEBABRATA CHAKRABORTY2, MAHUYA DAS3, SAMIR K SIDDHANTA4,*

    Journal of Polymer Materials, Vol.38, No.1-2, pp. 21-34, 2021, DOI:10.32381/JPM.2021.38.1-2.3

    Abstract Elastomeric chlorosulfonated polyethylene (Hypalon) and thermoplastic polypropylene (PP) based thermoplastic Vulcanizates (TPVs) were prepared in presence of different doses of partial methyl ester of styrene-maleic anhydride copolymer (PMES-MA) as compatibilizer employing dynamic vulcanization technique. The mechanical analysis of the prepared TPVs exhibited significant improvements in stress at 25% modulus, ultimate tensile strength (UTS), and hardness values. FTIR studies revealed that a chemical interaction had taken place between hypalon and compatibilizer during the process of dynamic vulcanization which led to an enhancement of interfacial adhesion between them. The two-phase morphologies were clearly observed by scanning electron microscopic studies. The Tg values… More >

  • Open Access

    ARTICLE

    Averaged Dynamics of Fluids near the Oscillating Interface in a Hele-Shaw Cell

    Anastasia Bushueva, Olga Vlasova, Denis Polezhaev*

    FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 847-857, 2024, DOI:10.32604/fdmp.2024.048271

    Abstract The steady flow in a Hele-Shaw cell filled with fluids with a high viscosity contrast in the presence of fluid oscillations is experimentally studied. The control of oscillatory dynamics of multiphase systems with interfaces is a challenging technological problem. We consider miscible (water and glycerol) and immiscible (water and high-viscosity silicone oil PMS-1000) fluids under subsonic oscillations perpendicular to the interface. Observations show that the interface shape depends on the amplitude and frequency of oscillations. The interface is undisturbed only in the absence of oscillations. Under small amplitudes, the interface between water and glycerol widens due to mixing. When the… More >

  • Open Access

    ARTICLE

    Linear and Non-Linear Dynamics of Inertial Waves in a Rotating Cylinder with Antiparallel Inclined Ends

    Mariya Shiryaeva1, Mariya Subbotina2, Stanislav Subbotin1,*

    FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 787-802, 2024, DOI:10.32604/fdmp.2024.048165

    Abstract This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends. In this setting, the cross-section of the cylinder is divided into two regions where the fluid depth increases or decreases with radius. Three different regimes are found: inertial wave attractor, global oscillations (the cavity’s resonant modes) and regime of symmetric reflection of wave beams. In linear wave regimes, a steady single vortex elongated along the rotation axis is generated. The location of the wave’s interaction with the sloping ends determines the vortex position and the vorticity sign. In non-linear… More >

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