http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
딤플형 판형 열교환기의 유동 및 전열특성에 대한 수치해석
안혁진(Hyuk Jin Ahn),이상혁(Sang Hyuk Lee),허남건(Nahmkeon Hur),박형준(Hyoung Joon Park),유해성(Hea Seong Ryu) 대한설비공학회 2010 설비공학 논문집 Vol.22 No.3
In the present study, the characteristics on the internal flow and heat transfer of the dimple-type plate heat exchanger were numerically investigated. For the numerical analysis, the conjugate heat transfer analysis between hot fluid-separating plate-cold fluid was performed using the periodic boundary condition at the center area of the plate and appropriate inlet and outlet conditions for the two streams. The numerical results were validated by the comparison with the experimental data. From these results, the correlations of the Colburn j-factor for the heat transfer and the Fanning f-factor for the flow friction were obtained. The present results could be applicable for the optimal design of dimple-type plate heat exchanger.
밀폐공간에서 수소 누설로 인한 수소 제트 확산에 대한 수치해석
안혁진(Hyuk Jin Ahn),이상혁(Sang Hyuk Lee),허남건(Nahmkeon Hur),이문규(Moon Kyu Lee),용기중(Geejoong Yong) 한국전산유체공학회 2009 한국전산유체공학회지 Vol.14 No.2
In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.
밀폐공간에서 수소 누설로 인한 수소 제트 확산에 대한 수치해석
안혁진(Hyuk Jin Ahn),이상혁(Sang Hyuk Lee),허남건(Nahmkeon Hur),이문규(Moon Kyu Lee),용기중(Geejoong Yong) 한국전산유체공학회 2009 한국전산유체공학회 학술대회논문집 Vol.2009 No.4
In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage lest of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate tire effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases call be used as a database in various applications for tire hydrogen safety.
안혁진(Hyuk-Jin Ahn),손홍석(Hong-Seok Son) 한국식품과학회 2012 한국식품과학회지 Vol.44 No.3
본 연구에서는 동일한 조건하에 온실 재배하여 수확한 7종의 포도를 선발하여 품종간의 이화학적 특성을 비교 분석하였다. 포도의 당, pH, 총산도 등의 일반성분 분석과 HPLC를 이용한 유기산 분석, ICP-OES를 이용한 미네랄 분석을 실시하였다. 당도는 V. vinifera종이 V. labrusca종에 비해 2-4°Bx 정도로 높게 나타났고, Seibel 품종이 20.93°Bx로 가장 높은 함량을 보였다. pH는 Chardonnay 및 Seibel 등이 4.01로 가장 높았으며, 총산도는 Steuben, Merlot, Cabernet Sauvignon 등이 0.9-1.0%로 다른 품종에 비해 높게 나타났다. Tartaric acid의 함량은 Merlot 품종이 과육과 과피에서 가장 높았으며, Steuben, Kyoho 품종은 상대적으로 낮은 함량을 보였다. Malic acid의 경우 Chardonnay와 Seibel 등의 백포도 품종이 적포도 품종에 비해 높은 함량을 보였다. Citric acid의 함량은 과육과 과피간의 유의적인 차이를 관찰할 수 없었고, Chardonnay와 Campbell Early의 과피에서는 검출되지 않았다. 미네랄 함량 중 potassium은 전체 미네랄 중 가장 높은 함량을 보였고, Chardonnay와 Seibel 등의 함량이 가장 높았으며, Steuben과 Campbell Early 등이 낮게 검출되었다. Calcium의 함량은 Kyoho 포도 품종이 가장 높았고, Magnesium의 함량은 Chardonnay가 가장 높았으며, Sodium의 함량은 Chardonnay, Seibel 등이 높게 나타났다. Chardonnay와 Seibel은 Calcium을 제외한 전체 미네랄 함량에서 모두 높은 수치로 검출되었다. The aim of this study was to describe the effects of genetic factors on the chemical composition or metabolites of grapes harvested within the same region. Grapes were separated into pulp, skin, and seed, and physicochemical characteristics were compared among seven grape varieties. The sugar concentrations of the grape musts ranged from 15.17-20.93°Bx with Seibel variety being highest at 20.93°Bx. pH ranges of grape musts were 3.46-4.02 and total acidity was highest with 1.05 in Steuben variety. Tartaric acid content was highest with 146.68, 500.10 ㎎/L in pulp and skin extract of Merlot variety. Malic acid content was highest in pulp extract of Seibel variety (1127.14 ㎎/L) and skin extract of Chardonnay variety (1720.06 ㎎/L). K content was highest with 379.13 and 828.01 ㎎/L in pulp and skin extract of Chardonnay variety. Ca content was highest in pulp extract of Kyoho variety (6.98 ㎎/L) and skin extract of Campbell Early variety (12.26 ㎎/L).
터널 내 수소연료 자동차의 수소 누설로 인한 수소 확산에 대한 수치해석 연구
안혁진(Hyuk Jin Ahn),정재혁(Jae Hyuk Jung),허남건(Nahmkeon Hur),이문규(Moon Kyu Lee),용기중(Geejoong Yong) 한국전산유체공학회 2010 한국전산유체공학회지 Vol.15 No.2
In the present study, a numerical simulation for the diffusion of hydrogen leakage of FCV(Fuel Cell Vehicle) in a tunnel was performed to aid the assessment of risk in case of leakage accident. The temporal and spatial distributions of the hydrogen concentration around FCV are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of tunnel ventilation system for relieving the accumulation of the leaked hydrogen gas. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.
용적조절호형방사선치료(VMAT)의 다중치료중심(Multi- Isocenter)을 이용한 치료 시, 접합부(Junction)의 선량 변화에 대한 고찰
정동민,박광순,안혁진,최윤원,박별님,권용재,문성공,이종운,정태식,박령황,김세영,김미정,백종걸,조정희,Jung, Dong Min,Park, Kwang Soon,Ahn, Hyuk Jin,Choi, Yoon Won,Park, Byul Nim,Kwon, Yong Jae,Moon, Sung Gong,Lee, Jong Oon,Jeong, Tae Sik,Park, Ry 대한방사선치료학회 2021 대한방사선치료학회지 Vol.33 No.-
용적조절호형방사선치료(Volumetric Modulated Arc Therapy)의 다중치료중심(Multi-Isocenter)을 이용하여 치료 시, 접합부(Junction)의 재현 오차에 따른 선량변화에 대해 고찰하였다. Arccheck Phantom에 임의의 치료부위를 설정하고, 다중치료중심에 대해 치료계획을 수립하였다. 그리고 X(왼쪽), Y(위쪽), Z(안쪽, 바깥쪽) 방향에 대해서 접합부의 오차를 0 ~ 4 mm로 설정 후 선형가속기를 이용하여 방사선을 조사하였고, 이 후 phantom을 통해 얻어진 점 선량(point dose)과 감마인덱스(gamma Index)를 통해 분석하였다. X방향과 Y방향에 대한 오차가 2, 4 mm 발생 했을 때, 감마패스율(점 선량)은 각각 99.3% (2.085), 98% (2.079 Gy) 와 98.5% (2.088), 95.5% (2.093 Gy)로 나타났다. 그리고 Z방향에 대해서 안쪽과 바깥쪽에 대한 오차가 1, 2, 4 mm 발생 했을 때, 감마패스율(점 선량)은 각각 94.8% (2.131), 82.6% (2.164), 72.8% (2.22 Gy) 와 93.4% (2.069), 90.6% (2.047), 79.7% (1.962 Gy) 로 보여졌다. X, Y방향에 대해서 4 mm 까지의 오차 결과는 허용오차 안에 있었으나, Z방향에 대해서는 1 mm 를 초과하는 오차 값에 대해서 허용오차 밖의 결과 값이 도출되었다. 이는 높은 선량 영역(high dose area)과 낮은 선량 영역(low dose area)에 대해 치료부위의 진행방향과 같은 방향의 오차가 선량 분포(dose distribution)가 더 민감하다는 것을 시사한다. 향후 지속적인 연구를 통해 기관차원의 셋 업(set up) 오차에 대한 가이드라인이 정립된다면, 접합부를 이용한 치료에서 양질의 치료를 제공할 수 있을 것이라 사료된다. This study examined dose change depending on the reposition error of the junction at the time of treatment with multi-isocenter volumetric modulated arc therapy. This study selected a random treatment region in the Arccheck Phantom and established the treatment plan for multi-isocenter volumetric modulated arc therapy. Then, after setting the error of the junction at 0 ~ 4 mm in the X (left), Y (upper), and Z (inner and outer) directions, the area was irradiated using a linear accelerator; the point doses and gamma indexes obtained through the Phantom were subsequently analyzed. It was found that when errors of 2 and 4 mm took place in the X and Y directions, the gamma pass rates (point doses) were 99.3% (2.085) and 98% (2.079 Gy) in the former direction and 98.5% (2.088) and 95.5% (2.093 Gy) in the latter direction, respectively. In addition, when errors of 1, 2, and 4 mm occurred in the inner and outer parts of the Z direction, the gamma pass rates (point doses) were found to be 94.8% (2.131), 82.6% (2.164), and 72.8% (2.22 Gy) in the former part and 93.4% (2.069), 90.6% (2.047), and 79.7% (1.962 Gy) in the latter part, respectively. In the X and Y directions, errors up to 4 mm were tolerable; however, in the Z direction, error values exceeding 1 mm were beyond the tolerance level. This suggests that for high and low dose areas, errors in the direction same as the progress direction in the treatment region have a more sensitive dose distribution. If the guidelines for set-up errors are established at the institutional level through continuous research in the future, it will be possible to provide good quality treatment using junctions.
열차 운행에 따른 상대식 승강장에서 지하철 승강장 스크린 도어 풍압해석
이명성(Myungsung Lee),안혁진(Hyuk Jin Ahn),원찬식(Chan-Shik Won),허남건(Nahmkeon Hur) 한국전산유체공학회 2008 한국전산유체공학회 학술대회논문집 Vol.2008 No.-
The pressure-transient on platform screen doors in side platforms caused by passing trains with various operating conditions have been investigated numerically. The transient compressible three-dimensional flow simulations are performed with actual operating conditions of two trains by adopting moving mesh technique. To achieve more realistic results, the detailed shape of train and the subway station including tunnels connecting the adjacent stations are represented in the computational domain. Numerical analyses are carried out for cases considering arriving/passing/departing train with or without train stopped on the opposite track, and both trains on the move in opposite direction. From the numerical results, the maximum pressure on the platform screen doors, which is predicted in the case of two passing trains, satisfied the design standards for similar stations.