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Particuology 2024年第12期95卷 319-332页

作者： Wassim Harizi Fathi Hamdi Mouldi Chrigui research unit“Mechanical modeling Materials and Energy”National School of Engineer of GabesUniversity of GabesGabes6029Tunisia

This research paper investigates a three-dimensional,two-phase flow dynamics,and atomization characteristics of a spill return *** method includes the internal flow field,primary and secondary atomization which are modeled using the hybrid approach Volume of Fluid to Discrete Phase Model(VOF to DPM).A comparison between the Large Eddy Simulation(LES)and The k-omega Shear Stress Transport turbulence model(SST k-ω)in combination with the Volume of Fluid(VOF)model,along with the Adaptive Mesh Refinement(AMR)method,to predict the breakup of the liquid core is carried *** investigation presents axial and tangential distributions of velocity,mean diameter,and spray cone angle of droplets at spray pressures of Spill-to-Feed Ratio(SFR)equal to *** numerical results are validated against the Phase-Doppler Anemometry(PDA)experiment.A relative error,of less than 7.3%,is *** study systematically explores the spatiotemporal evolution of the flow field,including the liquid surface wave motion,liquid film characteristics,and the formation/atomization of the fluid spray cone downstream of the injector.

关键词： VOF to DPM Spill return atomizer AMR Integral sauter mean diameter Turbulence

Distinct MLT asymmetry of auroral kilometric radiation observed by the FAST satellite

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Earth and Planetary Physics 2025年第1期9卷 188-193页

作者： JiaWen Tang Sai Zhang FuLiang Xiao HongMing Yang Si Liu YiHua He Chang Yang YuYue Jin ZhouKun Deng Ping Li Archie James Johnston School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China Hunan Province Higher Education Key Laboratory of modeling and Monitoring on the Near-Earth Electromagnetic Environments Changsha University of Science and TechnologyChangsha 410114China School of Electrical and Information Engineering Changsha University of Science and TechnologyChangsha 410114China

Auroral Kilometric Radiation (AKR) is a common radio emission,which can contribute to the magnetosphere-ionosphereatmosphere co u *** emissions have been observed in all magnetic planet magnetospheres of the solar *** this study,using observations from the FAST satellite from 30 August 1996 to 9 September 2001,the distribution of AKR in altitude=500-4500 km and invariant latitude (|ILAT|)=60°-80°has been analyzed.63045 AKR samples have been identified with~48%(52%) samples on the dayside (nightside).Of considerable interest,there is a distinct MLT asymmetry with the high occurrence rate in MLT=05-08 and 18-22(02-05 and 12-17) in the northern (southern) *** distinct MLT asymmetry is associated with the direction of Bxof the interplaneta ry magnetic *** addition,the occurrence rate on the nightside clearly increases as the AE^(*) index *** study further enriches the information and understanding of AKR in the magnetosphere as well as other similar radio emissions.

关键词： asymmetry auroral kilometric radiation interplanetary magnetic field

VOLUME SEGMENTATION BY POST-PROCESSING DATA FROM SIMULATION OF SOLIDIFICATION IN THE METAL CASTING PROCESS

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International Journal of modeling, Simulation, and Scientific Computing 2013年第S1期4卷 128-141页

作者： ELIZABETH JACOB M.MANOJ ROSCHEN SASIKUMAR Computational modeling and Simulation unit National Institute for Interdisciplinary Science and Technology Council of Scientific and Industrial research Trivandrum–695019 India

In the process of interpreting simulation results,new post-processing techniques are *** work presents a post-processing method that analyzes the solidification pattern formed by simulation of the solidification process of molten metal in a mold to produce shaped *** generally involve numerical solutions of differential equations which are discretized by dividing the three-dimensional computational domain into small finite volume elements using a 3D *** locations of the grid points and values of the solidification time at these locations are used to divide the spatial data into 3D sections such that starting from a hotspot location within the section that has high solidification time,there is a gradient outwards with lower values of solidification *** section is assumed to be fed by one or more feeders that must freeze only after the section has solidified *** volume of a feeder can be determined from the volume of the section it is supposed to *** volume and surface area of sections are determined approximately to calculate feeder size and *** post-processing algorithm is a simulation-based quantitative approach to feeder design which in conventional foundry practice has been more of an art than *** is also general enough for use in other 3D segmentation applications.

关键词： Metal casting simulation solidification pattern volume segmentation feeder design.

Using fracture-based continuum modeling of coupled geomechanical-hydrological processes for numerical simulation of hydraulic fracturing

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1582-1599页

作者： Goodluck I.Ofoegbu GNO modeling research LLC. San AntonioTX78253USA

This paper describes numerical simulation of hydraulic fracturing using fracture-based continuum modeling(FBCM)of coupled geomechanical-hydrological processes to evaluate a technique for high-density fracturing and fracture *** simulations are innovative because of modeling discrete fractures explicitly in continuum analysis.A key advantage of FBCM is that fracture initiation and propagation are modeled explicitly without changing the domain grid(*** re-meshing).Further,multiple realizations of a preexisting fracture distribution can be analyzed using the same domain *** simulated hydraulic fracturing technique consists of pressurizing multiple wells simultaneously:initially without permeating fluids into the rock,to seed fractures uniformly and at high density in the wall rock of the wells;followed by fluid injection to propagate the seeded fracture density *** combines the ease of continuum modeling with the potential accuracy of modeling discrete fractures and fracturing *** are modeled as piecewise planar based on intersections with domain elements;fracture geometry stored as continuum properties is used to calculate parameters needed to model individual fractures;and rock behavior is modeled through tensorial aggregation of the behavior of discrete fractures and unfractured *** are presented for previously unfractured rock and for rock with preexisting fractures of horizontal,shallow-dipping,steeply dipping,or vertical *** of a single-well model are used to determine the pattern and spacing for a multiple-well *** results illustrate high-density fracturing and fracture caging through simultaneous fluid injection in multiple wells:for previously unfractured rock or rock with preexisting shallow-dipping or horizontal fractures,and in situ vertical compressive stress greater than *** preexisting fractures are steeply dipping or vertical,and considering the same in situ

关键词： Discrete fracture Fracture-based continuum modeling Fracture caging High-density fracturing Hydraulic fracturing Preexisting fracture

Absorption of laser radiation in ultracold plasma

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Chinese Physics B 2016年第10期25卷 128-131页

作者： N Y Shaparev Institute of Computational modeling Russian Academy of Sciences National research Tomsk State University

In this paper, we analyze the spectral behavior(optical thickness, shape and linewidth) of laser radiation absorption under the correlation heating of ions in an ultracold plasma. The Voigt formula is used to find the absorption *** spectral line width is shown to grow with time while the optical thickness reduces. Our modeling results are in good agreement with the experimental findings reported in the literature.

关键词： absorption laser radiation ultracold plasma

Viscoelastic modeling of the diffusion of polymeric pollutants injected into a pipe flow

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Acta Mechanica Sinica 2013年第2期29卷 166-178页

作者： T.Chinyoka O.D. Makinde Center for research in Computational and Applied Mechanics University of Cape Town Institute for Advanced research in Mathematical modeling and Computations Cape Peninsula University of Technology

This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric *** influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer *** problem is solved numerically using a semi-implicit finite difference *** are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer *** model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water *** model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures.

关键词： Axi-symmetric flow·Polymeric pollutant dispersion·Oldroyd-B model Buoyancy forces·Semi-implicit finite difference method

A robust multi-objective and multi-physics optimization of multi-physics behavior of microstructure

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Journal of Central South University 2016年第12期23卷 3225-3238页

作者： Hamda Chagraoui Mohamed Soula Mohamed Guedri research unit in Structural Dynamics Modeling and Engineering of Multi-Physics SystemsSDMESMNabeul Preparatory Engineering Institute-IPEINUniversity of Carthage Laboratory of Applied Mechanics and Engineering ENITDepartment of Mechanical engineering ENSITTunis University of Tunisia

A new strategy is presented to solve robust multi-physics multi-objective optimization problem known as improved multi-objective collaborative optimization （IMOCO） and its extension improved multi-objective robust collaborative （IMORCO）. In this work, the proposed IMORCO approach combined the IMOCO method, the worst possible point （WPP） constraint cuts and the Genetic algorithm NSGA-II type as an optimizer in order to solve the robust optimization problem of multi-physics of microstructures with uncertainties. The optimization problem is hierarchically decomposed into two levels： a microstructure level, and a disciplines levels, For validation purposes, two examples were selected： a numerical example, and an engineering example of capacitive micro machined ultrasonic transducers （CMUT） type. The obtained results are compared with those obtained from robust non-distributed and distributed optimization approach, non-distributed multi-objective robust optimization （NDMORO） and multi-objective collaborative robust optimization （McRO）, respectively. Results obtained from the application of the IMOCO approach to an optimization problem of a CMUT cell have reduced the CPU time by 44% ensuring a Pareto front close to the reference non-distributed multi-objective optimization （NDMO） approach （mahalanobis distance, D2M =0.9503 and overall spread, So=0.2309）. In addition, the consideration of robustness in IMORCO approach applied to a CMUT cell of optimization problem under interval uncertainty has reduced the CPU time by 23% keeping a robust Pareto front overlaps with that obtained by the robust NDMORO approach （D2M =10.3869 and So=0.0537）.

关键词： multi-physics multi-objective optimization robust optimization collaborative optimization non-distributed anddistributed optimization uncertainty interval

Dispatchable Capability of Aggregated Electric Vehicle Charging in Distribution Systems

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Energy Engineering 2025年第1期122卷 129-152页

作者： ShiqianWang Bo Liu Yuanpeng Hua Qiuyan Li Binhua Tang Jianshu Zhou Yue Xiang Economic and Technology research Institute State Grid Henan Electric Power CompanyZhengzhou450052China College of Electrical Engineering Sichuan UniversityChengdu610065China

This paper introduces a method for modeling the entire aggregated electric vehicle(EV)charging process and analyzing its dispatchable *** methodology involves developing a model for aggregated EV charging at the charging station level,estimating its physical dispatchable capability,determining its economic dispatchable capability under economic incentives,modeling its participation in the grid,and investigating the effects of different scenarios and EV penetration on the aggregated load dispatch and dispatchable *** results indicate that using economic dispatchable capability reduces charging prices by 9.7%compared to physical dispatchable capability and 9.3%compared to disorderly ***,the peak-to-valley difference is reduced by 64.6%when applying economic dispatchable capability with 20%EV penetration and residential base load,compared to disorderly charging.

关键词： Aggregated charging dispatchable capability peak shaving and valley filling the economics of charging demand response

Characteristics of dew events in an arid artificial oasis cropland and a sub-humid cropland in China

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Journal of Arid Land 2016年第3期8卷 399-408页

作者： MENG Yao WEN Xuefa Key Laboratory of Ecosystem Network Observation and modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Dew is an important source of water which significantly influences the physiological status of vegetation and the microclimate environment. For quantifying the characteristics of dew events and analyzing the underlying mechanism of dew formation in different ecosystems, we measured, based on the flux-profile method, the amount, frequency and duration of dew events in two croplands, an arid artificial oasis cropland in Zhangye, Gansu province and a sub-humid cropland in Luancheng, Hebei province in China. The results showed that dew events were observed in a total of 69 days in Zhangye, which accounted for 59% of the growing season（from 28 May to 21 September, 2012）, while 128 days in Luancheng, which accounted for 79% of the growing season（from 5 April to 13 September, 2008）. The frequencies of dew events were 2.8 and 2.4 times of those of precipitation in Zhangye and Luancheng, respectively. In addition, the dew amount reached up to 9.9 and 20.2 mm in Zhangye and Luancheng, which accounted for 9.5% and 4.1% of precipitation, respectively. The average amount of dew was 0.14 and 0.16 mm/night in Zhangye and Luancheng, respectively and the duration of dew events ranged from 0.5 to 12.0 h in the two study sites. Dew amounts were associated with the gradient of atmospheric water vapor concentration and dew duration（P＆lt;0.001） in both the two sites. The result implies that dew events play a more important role in crop growth in arid areas in comparison to sub-humid areas considering the dew occurrence frequency and the amount per night.

关键词： dew amount frequency of dew duration of dew flux-profile

Topological modeling of a One Stage Spur Gear Transmission

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Chinese Journal of Mechanical Engineering 2014年第5期27卷 900-908页

作者： MILADI CHAABANE Mariem PLATEAUX Régis CHOLEY Jean-Yves KARRA Chafik RIVIERE Alain HADDAR Mohamed Mechanical Modeling and Manufacturing Unit National Engineering School of Sfax(ENIS) BP 1173 – 3038 – Sfax – Tunisia Laboratory of Engineering of the Mechanical Structures and Materials High Institute of Mechanic of Paris(SUPMECA)3 rue Fernand HainautNational 93407 Saint-Ouen Cedex Mechanical Modeling and Manufacturing Unit National Engineering School of Sfax(ENIS) BP 1173–3038–Sfax–Tunisia

Finding a basis of unification for the modeling of mechatronic systems is the search subject of several *** paper is a part of a general research designed to the application of topology as a new approach for the modeling of mechatronic ***,the modeling of a one stage spur gear transmission using a topological approach is *** approach is based on the concepts of topological collections and transformations and implemented using the MGS（modeling of general systems）*** topological collections are used to specify the interconnection laws of the one stage spur gear transmission and the transformations are used to specify the local behavior laws of its different *** order to validate this approach,simulation results are presented and compared with those obtained with MODELICA language using Dymola *** good results are achieved,this approach might be used as a basis of unification for the modeling of mechatronic systems.

关键词： topological modeling topological collections transformations MGS language one stage spur gear