• 제목/요약/키워드: Multi-physics simulation

검색결과 133건 처리시간 0.028초

300 kW 급 대용량 초전도 직류 유도가열로 개발 (Development Progress of a 300 kW-class HTS DC Induction Furnace)

  • 최종호;고병수;박희철;박민원;유인근;김석호;심기덕;조상호;조진식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.1112-1113
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    • 2015
  • In the end of 2014, Changwon National University and TECHSTEEL Co., Ltd. had initiated a project on the development of a 300 kW-class HTS DC Induction Furnace(HTS DC IF) for preheating non-ferrous metal billets funded by the Korea Institute of Energy Technology Evaluation and Planning for 3 years. This is the one of the most realistic commercial machines applying the coated conductors. In this paper, the development progress of a 300 kW-class HTS DC IF was introduced. The major characteristics of the furnace including its capacity, structure and operation scheme were presented. For ensuring the successful design, a pre-validation study was performed through the electromagnetic, heat transfer and solid mechanical analysis using a multi-physics FEM tool. The aluminum billet was heated up to $540^{\circ}C$ under 1 T of the magnetic flux density at the center of the billet, and the simulation results were described in detail.

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Analysis on Geo-stress and casing damage based on fluid-solid coupling for Q9G3 block in Jibei oil field

  • Ji, Youjun;Li, Xiaoyu
    • Geomechanics and Engineering
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    • 제15권1호
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    • pp.677-686
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    • 2018
  • Aimed at serious casing damage problem during the process of oilfield development by injecting water, based on seepage mechanics, fluid mechanics and the theory of rock mechanics, the multi-physics coupling theory was also taken into account, the mathematical model for production of petroleum with water flooding was established, and the method to solve the coupling model was presented by combination of Abaqus and Eclipse software. The Q9G3 block in Jibei oilfield was taken for instance, the well log data and geological survey data were employed to build the numerical model of Q9G3 block, the method established above was applied to simulate the evolution of seepage and stress. The production data was imported into the model to conduct the history match work of the model, and the fitting accuracy of the model was quite good. The main mechanism of casing damage of the block was analyzed, and some wells with probable casing damage problem were pointed out, the displacement of the well wall matched very well with testing data of the filed. Finally, according to the simulation results, some useful measures for preventing casing damage in Jibei oilfield was proposed.

유한요소법을 이용한 3차원 염해 침투 예측 모델의 개발 (Development of Three Dimensional Chloride Ion Penetration Model Based on Finite Element Method)

  • 최원;김한중
    • 한국농공학회논문집
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    • 제57권5호
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    • pp.43-49
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    • 2015
  • Most of agricultural structures located in seashore could not avoid rapid deterioration of concrete because chloride-ion and $CO_2$ gradually penetrate into concrete. However, since most of models can be able to describe the phenomenon of penetration by using one or two dimensional models based on finite difference method (FDM), those modes can not simulate the real geometry and it takes a lot of computational time to complete even the calculation. To overcome those weaknesses, three dimensional numerical model considering time dependent variables such as surface concentration of chloride and diffusion coefficient of domain based on finite element method (FEM) was suggested. This model also included the neutralization occurred by the penetration of $CO_2$. Because the model used various sizes of tetrahedral mesh instead of equivalent rectangular mesh, it reduced the computational time to compare with FDM. As this model is based on FEM, it will be easily extended to execute multi-physics simulation including water evaporation and temperature change of concrete.

보조동력장치 연료 공급용 서보밸브 토크모터의 기초 수치모사 연구 (Priliminary Numerical Simulation of the Torque Motor for a Servo Valve in the Fuel Supply System of APU)

  • 장세명;정헌술;장강원;양인영;이원중
    • 유공압시스템학회논문집
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    • 제6권2호
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    • pp.1-6
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    • 2009
  • The APU(Auxiliary Power Unit) needs a set of complex pipeline for the fuel supply system where some of the main valves controlling the flow rate consist of the servo valve worked with a torque motor. The input electric current produces an induced magnetic field almost perpendicular to the background magnetic filed generated by fixed permanent magnets. The induced torque deforms the tubular bushing, and directly rotates an armature, which can open and close the valve. In this study, we start from a basic analytic model using a simple electro-magneto-statics, and expand our model to the three-dimensional one computationally applying a commercial code named COMSOL. The result is compared with each other, and reasonable numerical data are obtained for the dynamic behavior and multi-physics system.

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Turbomachinery design by a swarm-based optimization method coupled with a CFD solver

  • Ampellio, Enrico;Bertini, Francesco;Ferrero, Andrea;Larocca, Francesco;Vassio, Luca
    • Advances in aircraft and spacecraft science
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    • 제3권2호
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    • pp.149-170
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    • 2016
  • Multi-Disciplinary Optimization (MDO) is widely used to handle the advanced design in several engineering applications. Such applications are commonly simulation-based, in order to capture the physics of the phenomena under study. This framework demands fast optimization algorithms as well as trustworthy numerical analyses, and a synergic integration between the two is required to obtain an efficient design process. In order to meet these needs, an adaptive Computational Fluid Dynamics (CFD) solver and a fast optimization algorithm have been developed and combined by the authors. The CFD solver is based on a high-order discontinuous Galerkin discretization while the optimization algorithm is a high-performance version of the Artificial Bee Colony method. In this work, they are used to address a typical aero-mechanical problem encountered in turbomachinery design. Interesting achievements in the considered test case are illustrated, highlighting the potential applicability of the proposed approach to other engineering problems.

THREE-DIMENSIONAL SIMULATION OF A ROTATING CORE-COLLAPSE SUPERNOVA

  • NAKAMURA, KO;KURODA, TAKAMI;TAKIWAKI, TOMOYA;KOTAKE, KEI
    • 천문학논총
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    • 제30권2호
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    • pp.481-483
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    • 2015
  • Multi-dimensionality in the inner working of core-collapse supernovae has long been considered one of the most important ingredients to understand the explosion mechanism. We perform a series of numerical experiments to explore how rotation impacts the 3-dimensional hydrodynamics of core-collapse supernova. We employ a light-bulb scheme to trigger explosions and a three-species neutrino leakage scheme to treat deleptonization effects and neutrino losses from the neutron star interior. We find that the rotation can help the onset of neutrino-driven explosions for models in which the initial angular momentum is matched to that obtained from recent stellar evolutionary calculations (${\sim}0.3-3rad\;s^{-1}$ at the center). For models with larger initial angular momenta, a shock surface deforms to be oblate due to larger centrifugal force. This makes a gain region, in which matter gains energy from neutrinos, more concentrated around the equatorial plane. As a result, the preferred direction of the explosion in 3-dimensional rotating models is perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that are often obtained from 2-dimensional simulations.

Porosity-dependent free vibration analysis of FG nanobeam using non-local shear deformation and energy principle

  • Gafour, Youcef;Hamidi, Ahmed;Benahmed, Abdelillah;Zidour, Mohamed;Bensattalah, Tayeb
    • Advances in nano research
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    • 제8권1호
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    • pp.37-47
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    • 2020
  • This work focuses on the behavior of non-local shear deformation beam theory for the vibration of functionally graded (FG) nanobeams with porosities that may occur inside the functionally graded materials (FG) during their fabrication, using the non-local differential constitutive relations of Eringen. For this purpose, the developed theory accounts for the higher-order variation of transverse shear strain through the depth of the nanobeam. The material properties of the FG nanobeam are assumed to vary in the thickness direction. The equations of motion are derived from Hamilton's principle. Analytical solutions are presented for a simply supported FG nanobeam with porosities. The validity of this theory is verified by comparing some of the present results with other higher-order theories reported in the literature, the influence of material parameters, the volume fraction of porosity and the thickness ratio on the behavior mechanical P-FGM beam are represented by numerical examples.

Microscopic damping mechanism of micro-porous metal films

  • Du, Guangyu;Tan, Zhen;Li, Zhuolong;Liu, Kun;Lin, Zeng;Ba, Yaoshuai;Ba, Dechun
    • Current Applied Physics
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    • 제18권11호
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    • pp.1388-1392
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    • 2018
  • Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

Buckling analysis of FG plates via 2D and quasi-3D refined shear deformation theories

  • Lemya Hanifi Hachemi Amar;Fouad Bourada;Abdelmoumen Anis Bousahla;Abdelouahed Tounsi;Kouider Halim Benrahou;Hind Albalawi;Abdeldjebbar Tounsi
    • Structural Engineering and Mechanics
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    • 제85권6호
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    • pp.765-780
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    • 2023
  • In this work, a novel combined logarithmic, secant and tangential 2D and quasi-3D refined higher order shear deformation theory is proposed to examine the buckling analysis of simply supported uniform functionally graded plates under uniaxial and biaxial loading. The proposed formulations contain a reduced number of variables compared to others similar solutions. The combined function employed in this study ensures automatically the zero-transverse shear stresses at the free surfaces of the structure. Various models of the material distributions are considered (linear, quadratic, cubic inverse quadratic and power-law). The differentials stability equations are derived via virtual work principle with including the stretching effect. The Navier's approach is applied to solve the governing equations which satisfying the boundary conditions. Several comparative and parametric studies are performed to illustrates the validity and efficacity of the proposed model and the various factors influencing the critical buckling load of thick FG plate.

Short packet communication in underlay cognitive network assisted by an intelligent reflecting surface

  • Pham Ngoc Son;Tran Trung Duy;Pham Viet Tuan;Tan-Phuoc Huynh
    • ETRI Journal
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    • 제45권1호
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    • pp.28-44
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    • 2023
  • We propose short packet communication in an underlay cognitive radio network assisted by an intelligent reflecting surface (IRS) composed of multiple reconfigurable reflectors. This scheme, called the IRS protocol, operates in only one time slot (TS) using the IRS. The IRS adjusts its phases to give zero received cumulative phase at the secondary destination, thereby enhancing the end-to-end signal-to-noise ratio. The transmitting power of the secondary source is optimized to simultaneously satisfy the multi-interference constraints, hardware limitations, and performance improvement. Simulation and analysis results of the average block error rates (BLERs) show that the performance can be enhanced by installing more reconfigurable reflectors, increasing the blocklength, lowering the number of required primary receivers, or sending fewer information bits. Moreover, the proposed IRS protocol always outperforms underlay relaying protocols using two TSs for data transmission, and achieves the best average BLER at identical transmission distances between the secondary source and secondary destination. The theoretical analyses are confirmed by Monte Carlo simulations.