http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
정해준(Haijun Jeong),현승환(Seounghwan Hyeon),이관수(Kwan-soo Lee) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
An experimental study was conducted for the investigation of the frosting under cryogenic forced convection conditions. Liquid nitrogen was used to maintain the temperature of the cooling surface at a cryogenic temperature. Under the cryogenic condition, the fog was observed in which ice particles flew above the cooling surface, and the fog phenomenon is a characteristic of cryogenic frosting that did not occur in general low-temperature. At the initial stage of the frosting experiment, the average frost thickness of the cryogenic conditions and the general low-temperature showed a similar tendency, but the density of the frost under the cryogenic conditions was very low. As time passed, the average frost thickness of the cryogenic temperature had a 67% larger value than that of the general low-temperature frost, but the difference was the only 6.7% in density.
승화 지배적 착상 현상을 모사할 수 있는 착상 해석 모델
이재환(Jaehwan Lee),정해준(Haijun Jeong),김강율(Gangyul Kim),이관수(Kwan-Soo Lee) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
When the frost layer grows under the extra-low cooling surface temperature, the phase change appears as a desublimation rather than freezing after condensation. However, the previous frosting models were established under the conditions favorable for freezing after condensation. The purpose of this study is to propose the frosting model based on the commercial software (Ansys fluent). The proposed model can predicts the growth behavior of frost layer under the conditions favorable for desublimation. In the numerical model, new mass transfer rate which can consider the water penetration into the frost layer was developed. The model was validated by experimental results at a cooling surface temperature of -40°C or less, where desublimation occurs predominantly. The frosting model predicts the growth of frost thickness and density within the maximum error of 15%. Furthermore, the frost layer growth was visualized using the frosting model.