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수치해석을 이용한 친환경 자동차용 전력변환장치의 유로 변화에 따른 냉각 성능 예측에 관한 연구
노정훈(J.H. Noh),이현경(H.K. Lee),고동신(D.S. Ko),허덕재(D.J. Hur) 한국전산유체공학회 2018 한국전산유체공학회지 Vol.23 No.4
In this study, the cooling performance of various cooling water channels was evaluated by numerical analysis in order to reduce the weight reduction, miniaturization and high efficiency of the power converter (DC-DC converter) mounted on the electric vehicle. As the analysis environment, heat sources (Diode, Rectifier, Inductors) have the constant heat generation values and fixed position. The pressure drop, internal maximum temperature and calorific value recovered by the cooling water were predicted according to the change of volume flow rate and cooling water flow direction. From the results, it was confirmed that the performance were changed according to the cooling channel pattern at the same volume flow rate, and the amount of volume flow rate at each pattern. In addition, it was found that the direction of the cooling water is an important factor for determining the cooling performance, and the optimum design of heat source layout is required for improving the cooling performance. The results obtained from this study would provide an important guideline for designing the cooling instrument as well as power conversion system, and would be helpful in selecting the dominant factors for the optimum design.
수소 탱크의 낙하 시험 환경 조건 결정을 위한 풍하중하의 거동 해석
이예승(Y.S. Lee),허덕재(D.J. Hur) 한국전산유체공학회 2021 한국전산유체공학회지 Vol.26 No.3
In general, gaseous hydrogen is stored under high pressure due to its low density. So, hydrogen tanks for transportation must undergo rigorous safety evaluation to protect passengers. In this study, the behavior analysis through flow analysis was performed to determine the environmental conditions of the drop test, which is a test to evaluate the impact durability of hydrogen tanks. That is, according to the wind speed, the change of the pressure distribution and displacement and rotation angle of the hydrogen tank were analyzed. As a result of the analysis, it was found that the acceleration of the hydrogen tank showed a relatively small change even when the wind speed was high, and the displacement of the hydrogen tank was within a controllable range. However, when the wind speed increases, the increase in the rotation angle of the hydrogen tank appears to be large. Therefore, it was found that the wind speed criteria for the experiment should be limited to a certain speed in order to increase the reliability of the test results.