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SAC/Sn58Bi 입자를 이용한 저온소결식 Multiscale Wick의 모세관 성능 측정
김성현(Sung Hyoun Kim),강서연(Seo Yeon Kang),조경진(Kyung Jin Cho),장석필(Seok Pil Jang) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
In this study, the capillary performance of multiscale wicks fabricated by using low-temperature sintering of SAC/Sn58Bi nanoparticles on the surface of screen mesh wicks is experimentally investigated. To manufacture multiscale wicks, a mixture of SAC305 (Sn 96.5%-Ag 3%-Cu 0.5%) and Sn58Bi (Sn 58%-Bi 42%) nanoparticles dispersed in ethanol is sprayed onto a screen mesh wick heated over 150 ℃. Capillary performance, which can be defined by the ratio of the permeability per effective pore radius, is obtained by measuring the absorbed mass of the fluid per unit time to the vertical direction based on the Rate-of-Rise Method. As a result, it is observed that the capillary performance of the multiscale wick increases in proportion to the mass of sintered particles. In addition, the effective pore radius is measured by using the maximum absorbed height of the fluid in the steady state. Based on the results, the capillary performance of the multiscale wick is enhanced up to 12% although the permeability decreases about 10 % because the effective pore radius is more decreased than that of the permeability.
The Optimal Design of Low Noise of the Engine Cooling Fan using Kriging Method
Hyoun-Jin Sim(심현진),Sung-Hyoun Kim(김성현),Je-Seon Ryu(류제선),Kyung-Joon Cha(차경준),Jung-Yoon Lee(이정윤),Jae-Eung Oh(오재응) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11
This paper proposes an optimal design scheme to reduce the noise of the engine cooling fan by adapting Kriging with two meta-heuristic techniques. An engineering model has been developed for the prediction of the noise spectrum of the engine cooling fan. The noise of the fan is expressed as the discrete frequency noise peaks at the BPF and its harmonics and line spectrum at the broad band by noise generation mechanisms. The object of this paper is to find the Optimal Design for Noise Reduction of the Engine Cooling Fan. We firstly show a comparison of the measured and calculated noise spectra of the fan for the validation of the noise prediction program. Orthogonal array is applied as design of experiments because it is suitable for Kriging. With these simulated data, we can estimate a correlation parameter of Kriging by solving the nonlinear problem with genetic algorithm and find an optimal level for the noise reduction of the cooling fan by optimizing Kriging estimates with simulated annealing. We notice that this optimal design scheme gives noticeable results. Therefore, an optimal design for the cooling fan is proposed by reducing the noise of its system.
적외선 램프 가열방식을 이용한 태양전지 셀의 솔더링 공정 및 열처리 조건 별 특성 평가
손형진(Hyoun Jin Son),이정진(Jung Jin Lee),김성현(Sung Hyun Kim) 한국태양광발전학회 2016 Current Photovoltaic Research Vol.4 No.2
A key point of a soldering process for photovoltaic (PV) modules is to increase an adhesive strength leading a low resistivity between ribbon and cell. In this study, we intended to optimize a heating condition for the soldering process and characterize the soldered joint via physical and chemical analysis methods. For the purpose, the heating conditions were adjusted by IR lamp power, heating time and hot plate temperature for preheating a cell. Since then the peel test for the ribbon and cell was conducted, consequently the peel strength data shows that there is some optimum soldering condition. In here, we observed that the peel strength was modified by increasing the heating condition. Such a soldering property is affected by a various factors of which the soldered joint, flux and bus bar of the cell are changed on the heating condition. Therefore, we tried to reveal causes determining the soldering property through analyzing the soldered interface.