http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
대류확산문제의 유한요소해석을 위한 Line-by-Line 해법
유재석,Yoo, Jaisuk 대한설비공학회 1991 설비공학 논문집 Vol.3 No.2
Finite element method has been developed recently for the solution of the convection-diffusion problems. Finite element method has several advantages over finite difference method, but its requirement of the larger memory size of the computer has prevented from wide application. In the present study, line-by-line technique has been implemented to finite element method to overcome this disadvantage. Two dimensional laminar natural convection in square cavity was chosen as an example in this study. The numerical result shows good agreement with bench mark solution and the size of the coefficient marix has been reduced drastically.
가솔린 차량의 각 요소별 연료소모량 분석을 위한 실험적 연구
유정철(Jengcheol Yoo),송해박(Haibak Song),박경석(Kyungseok Park),유재석(Jaisuk Yoo),박영무(Youngmoo Park),이종화(Jonghwa Lee) 한국자동차공학회 2002 한국자동차공학회 Symposium Vol.2002 No.11
A vehicle fuel economy is one of the most important issues in view of environmental regulation and customer’s<br/> needs. In order to improve the vehicle fuel economy, great efforts has been carried out on the components bases .<br/> However, systematic analysis of vehicle fuel consumption is necessary for the further improvement of vehicle fuel<br/> economy. In this paper, a methodology for the breakdown of vehicle fuel consumption was studied and proposed for<br/> systematic analysis of the vehicle fuel economy. The energy equation for the vehicle power train was set up for the<br/> analysis of the vehicle fuel economy and simplified to be calculated or estimated using the measured data in a<br/> vehicle. The amount of fuel that was used in vehicle components under arbitrary driving conditions was quantified.
형광 나노 포러스 박막을 이용한 표면 온도 센서의 제작 및 성능 연구 II
김현정(Hyun Jung Kim),유재석(Jaisuk Yoo),박진일(Jinil Park) 대한설비공학회 2013 설비공학 논문집 Vol.25 No.12
We present a non-invasive technique to the measure temperature distribution in nano-sized porous thin films by means of the two-color laser-induced fluorescence (2-LIF) of rhodamine B. The fluorescence induced by the green line of a mercury lamp with the makeup of optical filters was measured on two separate color bands. They can be selected for their strong difference in the temperature sensitivity of the fluorescence quantum yield. This technique allows for absolute temperature measurements by determining the relative intensities on two adequate spectral bands of the same dye. To measure temperature fields, Silica (SiO2) nanoporous structure with 1-um thickness was constructed on a cover glass, and fluorescent dye was absorbed into these porous thin films. The calibration curves of the fluorescence intensity versus temperature were measured in a temperature range of 10-60℃, and visualization and measurement of the temperature field were performed by taking the intensity distributions from the specimen for the temperature field.
형광 나노 포러스 박막을 이용한 표면 온도 센서의 제작 및 성능 연구 I
김현정(Hyun Jung Kim),유재석(Jaisuk Yoo),박진일(Jinil Park) 대한설비공학회 2013 설비공학 논문집 Vol.25 No.12
In this study, specimens with nano-sized porous thin films were manufactured by injecting fluorescence solution into the pores. We intended to find out the difference of the fluorescence intensity in each region of the specimen through an experimental apparatus that makes a temperature field. Before conducting experiments, the optimized manufacturing conditions were determined by analysis of all parameters that influence the emission intensity, and the experiments were carried out with the specimens produced in the optimized conditions. Then, the calibration curves of the fluorescence intensity versus temperature were performed by taking the intensity distributions from the specimen in various temperature fields. The surfaces of specimens were coated with Rhodamine-B (Rh-B) fluorescent dye and measured based on the fluorescence intensity. Silica (SiO2) nanoporous structure with 1-um thickness was constructed on a cover glass, and fluorescence dye was absorbed into these porous thin films.
순수금속에 대한 고온에서의 비접촉식 열확산계수 측정에 관한 연구
이광재(Kwangjae Lee),유재석(Jaisuk Yoo),이종화(Jonghwa Lee),김현정(HyunJung Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
The photothermal displacement method has been known as a useful technique to measure the thermal conductivity and thermal diffusivity. However, the previous measurements of thermal properties have been performed only at a room temperature. But it is not valid for all temperature range because of phonon and phonon-electron scattering in high temperature. So, in order to obtain the thermal diffusivity of pure metals in corresponding to increases a temperature, the surrounding of a sample should be heated and kept at steady state temperature conditions. In this study, the new experimental equipment is designed to satisfy these conditions. The thermal diffusivity of metals in the variation of a temperature is able to be measured with a high accuracy using the photothermal displacement method.
상변화 물질을 이용한 에너지의 저장에 관한 연구 - 핀이 부착된 열싸이폰의 이용에 관하여 -
김권진(Kwon Jin Kim),유재석(Jaisuk Yoo),김기현(Ki Hyun Kim) 한국태양에너지학회 1991 한국태양에너지학회 논문집 Vol.11 No.1
파라핀 왁스에 열에너지를 저장하기 위해 열전달 기구로 원판형 핀이 달린 열싸이폰을 사용하였다. 실험은 4, 6, 8개의 핀에 대해 수행되었으며 각각의 경우 왁스의 초기 온도와 주입열량을 변화시키면서 실험을 반복하였다. 실험을 통하여 특히 잠열 축열계의 전열경로의 주요지점에서의 열전달 특성을 규명하고자 하였으며 주요 결론은 다음과 같다.<br/> (1) 열싸이폰의 열관류율과 총합열관류율은 핀의 수가 증가함에 따라 커지나 핀과 왁스사이의 열전달계수는 감소하였다.<br/> (2) 핀에 의해 열전달이 촉진됨으로서 핀이 없는 열싸이폰에서 일어나는 dry-out 현상이 제거되었다.<br/> (3) 수평형의 핀은 왁스의 큰 규모의 대류를 억제하며 핀의 수가 증가함에 따라 핀 사이에서의 국소대류도 더욱 억제되었다. A two-phase closed thermosyphon with circular fins was used as the heat transfer device for storing the thermal energy in paraffin wax. Experiments were carried out for 4, 6 and 8 fins and for various initial temperatures of the wax and power inputs. Heat transfer characteristics along the heat flow path were investigated as well as the overall performance of the system.<br/> Some of the important results are as follows: (1) The thermosyphon heat transfer coefficient and the overall heat transfer coefficient increased with the number of fins, whereas the heat transfer coefficient between the fin and the wax decreased; (2) Facilitation of heat transfer by the fins seemed to alleviate the dry-out phenomenon that had been reported to occur in case of bare thermosyphon; and (3) The horizontal fins had adverse effect of subduing a full scale convection in the wax, and the increase of the number of fins delayed the onset of local convection between the fins.