• Title/Summary/Keyword: comsol

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Development of User-friendly Modeling Interface for Process-based Total System Performance Assessment Framework (APro) for Geological Disposal System of High-level Radioactive Waste (고준위폐기물 심층처분시스템에 대한 프로세스 기반 종합성능평가 체계(APro)의 사용자 친화적 모델링 인터페이스 개발)

  • Kim, Jung-Woo;Lee, Jaewon;Cho, Dong-Keun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.2
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    • pp.227-234
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    • 2019
  • A user-friendly modeling interface is developed for a process-based total system performance assessment framework (APro) specialized for a generic geological disposal system for high-level radioactive waste. The APro modeling interface is constructed using MATLAB, and the operator splitting scheme is used to combine COMSOL for simulation of multiphysics and PHREEQC for the calculation of geochemical reactions. As APro limits the modeling domain to the generic disposal system, the degree of freedom of the model is low. In contrast, the user-friendliness of the model is improved. Thermal, hydraulic, mechanical and chemical processes considered in the disposal system are modularized, and users can select one of multiple modules: "Default process" and multi "Alternative process". APro mainly consists of an input data part and calculation execution part. The input data are prepared in a single EXCEL file with a given format, and the calculation part is coded using MATLAB. The final results of the calculation are created as an independent COMSOL file for further analysis.

A New Unified Design Environment for Optimization of Electric Machines Based on Continuum Sensitivity and B-Spline Parametrization

  • Kim, Min-Ho;Lee, Hyang-Beom;Kim, Hyeong-Seok;Byun, Jin-Kyu
    • Journal of Electrical Engineering and Technology
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    • v.6 no.4
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    • pp.513-518
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    • 2011
  • In this paper, a unified design environment is developed for the optimization of electric machines based on continuum sensitivity. For electromagnetic (EM) system analysis, COMSOL scripting environment is used. Optimization module is developed by MATLAB programming, which can be combined with COMSOL script commands. The modules are combined into one MATLAB project, and iteration process necessary for the optimization of EM system can be performed efficiently. During the design process, visual feedback of the current design status is given to the designer. In addition, the B-Spline parametrization of the nodal points is implemented to obtain smooth boundary of the device. The developed software is applied to the problem of finding uniform flux density distribution at the air gap of an electromagnet to verify its feasibility and effectiveness.

The Development of Converting Program from Sealed Geological Model to Gmsh, COMSOL for Building Simulation Grid (시뮬레이션 격자구조 제작을 위한 Mesh 기반 지질솔리드모델의 Gmsh, COMSOL 변환 프로그램 개발)

  • Lee, Chang Won;Cho, Seong-Jun
    • Journal of the Korean earth science society
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    • v.38 no.1
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    • pp.80-90
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    • 2017
  • To build tetrahedra mesh for FEM numerical analysis, Boundary Representation (B-Rep) model is required, which provides the efficient volume description of an object. In engineering, the parametric solid modeling method is used for building B-Rep model. However, a geological modeling generally adopts discrete modeling based on the triangulated surface, called a Sealed Geological Model, which defines geological domain by using geological interfaces such as horizons, faults, intrusives and modeling boundaries. Discrete B-Rep model is incompatible with mesh generation softwares in engineering because of discrepancies between discrete and parametric technique. In this research we have developed a converting program from Sealed Geological Model to Gmsh and COMSOL software. The developed program can convert complex geological model built by geomodeling software to user-friendly FEM software and it can be applied to geoscience simulation such as geothermal, mechanical rock simulation etc.

Development of High Frequency pMUT Based on Sputtered PZT

  • Lim, Un-Hyun;Yoo, Jin-Hee;Kondalkar, Vijay;Lee, Keekeun
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2434-2440
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    • 2018
  • A new type of piezoelectric micromachined ultrasonic transducer (pMUT) with high resonant frequency was developed by using a thin lead zirconate titanate (PZT) as an insulation layer on a floating $10{\mu}m$ silicon membrane. The PZT insulation layer facilitated acoustic impedance matching at active pMUT, leading to a high performance in the acoustic conversion property compared with the transducer using $SiO_2$ insulation layer. The fabricated ultrasonic devices were wirelessly measured by connecting two identical acoustic transducers to two separate ports in a single network analyzer simultaneously. The acoustic wave emitted from a transducer induced a $3.16{\mu}W$ on the other side of the transducer at a distance of 2 cm. The transducer performances in terms of device diameters, PZT thickness, annealings, and different DC polings, etc. were investigated. COMSOL simulation was also performed to predict the device performances prior to fabrication. Based on the COMSOL simulation, the device was fabricated and the results were compared.

Case studies for modeling magnetic anomalies with COMSOL Multiphysics® (콤솔 멀티피직스를 활용한 지자기장 모델링 사례 연구)

  • Ha, Goeun;Kim, Seung-Sep
    • Journal of the Geological Society of Korea
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    • v.54 no.6
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    • pp.677-682
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    • 2018
  • Magnetic anomalies are sensitive to magnetic properties present in deep Earth and near surface structures. Such geophysical characteristics often can be quantified by numerical analyses. In this study, we developed a finite element method (FEM) approach to compute magnetic anomalies using COMOL $Multiphysics^{(R)}$. This FEM approach was verified by comparing its numerical results with the previously known analytic solution for a uniformly magnetized sphere. Then, we used the method to compute magnetic reversal patterns near mid-ocean ridge with various faulting scenarios. This COMSOL-based approach can be incorporated into advanced multi-physical numerical models to understand the Earth.

A benchmark for two-dimensional numerical subduction modeling using COMSOL Multiphysics® (콤솔 멀티피직스를 활용한 2차원 수치 섭입모델링 벤치마크)

  • Yu, Suhwan;Lee, Changyeol
    • Journal of the Geological Society of Korea
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    • v.54 no.6
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    • pp.683-694
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    • 2018
  • Subduction has been the focal point of numerical studies for decades because it plays an important role in the Earth's mass and energy circulations and generates earthquakes and arc volcanoes which are closely related to the human lives. Among the studies on subduction, numerical modeling has been broadly applied to the quantitative studies on the subducting slab in the mantle which cannot be directly observed. In this study, we benchmark the numerical subduction modeling using a finite element package, COMSOL $Multiphysics^{(R)}$ and the results are consistent with the previously reported benchmark results.

Thermal Flux Analysis for the Wearable NOx Gas Sensors (웨어러블 NOx 가스센서의 열유동 해석)

  • Jang, Kyung-uk
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.793-799
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    • 2019
  • In this study, the diffusion process and the thermal energy distribution gradient of the sensor were confirmed by using the finite element analysis program (COMSOL) of the mesh method to analyze the thermal diffusion in the wearable fabric (Nylon) + MWCNT gas sensor. To analyze the diffusion process of thermal energy, the structure of the gas sensor was modeled in a two dimension plane. The proposed modeling was presented with the characteristic value for the component of the sensor, and the gas sensor designed using the mesh finite element method (FEM) was proposed and analyzed by suggesting the one-way partial differential equation in the governing equation to know the degree of thermal energy diffusion and the thermal energy gradient. In addition, the temperature gradient 10[K/mm] of the anode-cathode electrode layer and the gas detection unit was investigated by suggesting the heat velocity transfer equation.

Development for Prediction Model of Disaster Risk through Try and Error Method : Storm Surge (시행 착오법을 활용한 재난 위험도 예측모델 개발 : 폭풍해일)

  • Kim, Dong Hyun;Yoo, HyungJu;Jeong, SeokIl;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.2
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    • pp.37-43
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    • 2018
  • The storm surge is caused by an typhoons and it is not easy to predict the location, strength, route of the storm. Therefore, research using a scenario for storms occurrence has been conducted. In Korea, hazard maps for various scenarios were produced using the storm surge numerical simulation. Such a method has a disadvantage in that it is difficult to predict when other scenario occurs, and it is difficult to cope with in real time because the simulation time is long. In order to compensate for this, we developed a method to predict the storm surge damage by using research database. The risk grade prediction for the storm surge was performed predominantly in the study area of the East coast. In order to estimate the equation, COMSOL developed by COMSOL AB Corporation was utilized. Using some assumptions and limitations, the form of the basic equation was derived. the constants and coefficients in the equation were estimated by the trial and error method. Compared with the results, the spatial distribution of risk grade was similar except for the upper part of the map. In the case of the upper part of the map, it was shown that the resistance coefficient, k was calculated due to absence of elevation data. The SIND model is a method for real-time disaster prediction model and it is expected that it will be able to respond quickly to disasters caused by abnormal weather.