http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
연료전지 전극(Cathode)의 성능해석 및 설계에 관한 연구
김홍건(H. G. Kim),강성수(S. S. Kang),곽이구(L. K. Kwac),송하영(H. Y. Song),강영우(Y. W. Kang) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.1
The cathode design is one of the most important parts in order to enhance the performance of fuel cells. A 3-D model of the porous oxygen reducing cathode with perforated current collectors is analysed for the enhanced design in fuel cells. Simulation is performed using equations of electric potential balance, momentum balance, and mass balance. The gas concentrations are quite large and are significantly affected by the reactions that take place. The weight fraction of oxygen, velocity field for the gas phase, and local overvoltage are illustrated in the porous reactive cathode layer. The current density is also analysed and the result shows the distribution and variation are stated in a wide range. It is found that the rate of reaction and the current production is higher beneath the orifice, and decreases as the distance to the gas inlet increases. The significance of the results is discussed in the viewpoint of the mass transportation phenomena, which is inferred that the mass transport of reactants dictates the efficiency of the electrode in this design and at these conditions.
김홍건(H. G. Kim),고범용(B. Y. Go),강영우(Y. W. Kang),박명모(M. M. Park) 한국생산제조학회 2005 한국공작기계학회 추계학술대회논문집 Vol.2005 No.-
This study did the grinding processing of a carbon-ceramic disc and found out the processing characteristic. The grinding processing used the diamond resin wheel and processed. A wear of the diamond wheel and Load are big but are the stability relatively. The width of the change of a surface roughness is small. Therefore Grinding characteristics got good result.
불연속 섬유강화 고분자 복합재료의 응력해석에 관한 연구
김홍건(H. G. Kim) 한국생산제조학회 2008 한국생산제조학회지 Vol.17 No.3
A composite mechanics for discontinuous fiber reinforced polymer matrix composites(PMC) is analysed in order to predict fiber axial stresses. In continuum approach, frictional slip which usually takes place between fibers and polymers is accounted to derive PMC equations. The interfacial friction stress is treated by the product of the coefficient of friction and the compressive stress normal to the fiber/matrix interface. The residual stress and the Poisson's contraction implemented by the rule of mixture(ROM) are considered for the compressive stress normal to the fiber/matrix interface. In addition, the effects of fiber aspect ratio and fiber volume fraction on fiber axial stresses are evaluated using the derived equations. Results are illustrated numerically using the present equations with reasonable materials data. It is found that the fiber axial stress in the center region shows no great discrepancy for different fiber aspect ratios and fiber volume fractions while some discrepancies are shown in the fiber end region.
압력조건의 변화에 따른 PEMFC의 성능 시뮬레이션 및 설계에 관한 연구
김홍건(H. G. Kim),김유신(Y. S. Kim),김홍열(H. Y. Kim),양성모(Y. M. Yang),나석찬(S. C. Nah) 한국생산제조학회 2005 한국공작기계학회 추계학술대회논문집 Vol.2005 No.-
Fuel cells are devices that convert chemical energy directly into electrical energy. Among many kinds of the fuel cell, Polymer electrolyte membrane fuel cell is such kind of thing which work under low temperature. Unfortunately, there are still many problems to be solved in order to make them into commercial use, such as the thermal and water management in working process of Polymer electrolyte membrane fuel cell. To solve the difficulties facing the researcher, the analysis of the inner mechanism of Polymer electrolyte membrane fuel cell should be implement as much as possible, mathematical modeling is an important tool for the reach of the fuel cell especially with the combination of experiment. By regarding some of the assumptions and simplifications, using the finite element technique, a two-dimensional electrochemical mode is created in this paper for the further comparison with experiment data. Based on the principals of the problem, the equation of electronic charge conservation equation, gas-phase continuity equation, and mass balance equation are used in calculating. In the end, the model results indicate the some of the phenomenon in the unit cell, and the relationships of potential and current density.
김홍건(H. G. Kim) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.3
2-D model of fluid flow, mass transport and electrochemistry is analysed to examine the effect of current density at the current collector depending on active layer thickness of catlyst in polymer electrolyte fuel cells. The finite element method is used to solve the continuity, potential and Maxwell-Stefan equations in the flow channel and gas diffusion electrode regions. For the material behavior of electrode reactions in the active catalyst layers, the agglomerate model is implemented to solve the diffusion-reaction problem. The calculated model results are described and compared with the different thickness of active catalyst layers. The significance of the results is discussed in the viewpoint of the current collecting capabilities as well as mass transportation phenomena, which is inferred that the mass transport of reactants dictates the efficiency of the electrode in the present analysis.