• Journal of Chest Surgery
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• 제6권1호
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• pp.51-56
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• 1973

This is one case report of successful resection of the aneurysm of the thoracic aorta, which det-ected by thoractomy unexpectedly, in the Department of Thoracic Surgery, Hanyang University Hospital. The patient was a 34 years old woman and subjective complaints was not related with the aneurysm. Chest film showed a small round hazy shadow in the left margin of the upper posterior mediastinum. A saccular aneurysm located on the descending thoracic aorta, 7cm distal to the left subclavian artery and arouse from the antero-lateral wall of the aorta. Excision of the saccular aneurysm was performed by cross clamping the descending aorta above and below the aneurysm, and then the defect of the aortic wall was closed by aortorrhaphy with continuous suture. Crossclamping time was required 15 minute. Histopathologically, the wall of the aneurysm consisted of all layers of the arterial wall, that is, intima, media and adventitia. Postoperative course was uneventful and aortogram showed good continuity of the blood flow of the entire aorta.

• 한국디지털건축인테리어학회논문집
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• 제12권3호
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• pp.5-13
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• 2012

In this study, features and design effects of PV(Photovoltaic) modules were classified to help the installation of BIPV(Building Integrated Photovoltaic) In addition, through domestic and international trends and cases survey, installation method was organized and applicable range of efficiency and design from First-generation solar cells to the third-generation solar cell was classified. Frist, Crystalline Solar cell module of first-generation is appropriate for the wall type, roof, louver, shading and etc. It has superiority of technology and price stability and can be achieved by a variety of aesthetic effects. Second, Dye-Sensitized Solar Cell of Thin Film solar cell can express a variety of colors, adjust light transmittance and maximize the aesthetic splendor. It is appropriate for the wall type, window type, curtain wall type and etc. Also, see-through type solar cell can provide comforts cause of free flow of light. And it is advantageous from economic due to adjust the indoor temperature. It is appropriate for the atrium type, curtain wall type, window type and etc.

• 한국전산유체공학회지
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• 제5권1호
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• pp.33-42
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• 2000

The LiBr-H₂O absorption process on a horizontal tube has been analyzed numerically. The flow field, which was calculated in the authors' previous study by solving the fully elliptic Navier-Stokes equations with accurate free-surface-tracking method, is used to solve the temperature and concentration distributions in the absorption film. With the assumption that the absorbent is linear, calculations have been made for various inlet temperature and flow-rate conditions. For low inlet temperature, the absorption rate is large in the upstream region but the mean temperature also increases and as a result the absorption decreases as the film flows to downstream while high-inlet-temperature case does the opposite. The difference in the absorption rate due to the inlet temperature change becomes smaller in the downstream than that in the upstream. For large flow rate, the heat transfer to the wall becomes poor due to the thick film and so does the absorption rate. The analyses have also been carried out for multiple tube arrangement and the results show that the absorption rate converges after a few tube rows.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.159-160
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• 2002

New S-shaped aeroelastic mesoflaps are utilized to control normal shock/boundary-layer interactions. New generation of the mesoflaps is designed f3r a better rigidness and a good flow uniformity across the ulteractions. ,Major advantages of the mesoflap system can be a better total pressure recovery downstream of the interactions due to the lambda shock structure over the flap system, and a rehabilitation of the thickened boundary layer due to bleeding through a cavity underneath the flap system. Skin friction has been measured downstream of the interactions, using the laser interferometer skin friction (LISF) meter, which optically detects the rate of thinning of an oil film applied to the test surface. Various flap-thicknesses of the S-shaped mesoflap arrays are tested, and the results are compared to the solid-wall reference case. Overall, not much difference in the level of skin friction is noticed for the S-shaped flap arrays of various thicknesses, and its level is lower than the skin friction downstream of the solid-wall interaction

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.90-96
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• 2003

Numerical analyses have been performed to obtain the absorption heat and mass transfer coefficients and the absorption mass flux from a falling film of LiBr solution. In the present study, the behavior of laminar-wavy falling film in the vertical absorber was studied analytically and experimentally. The change of absorption performance on mean film thickness, wave amplitude, wave celerity was analysed. The heat and mass transfer equations are solved simultaneously to give the temperature and concentration variations at the LiBr solution/refrigeration vapor interface and at the wall. Effects of uniform film, wavy film and film Reynolds number on the heat and mass transfer coefficients have been estimated. The analytical results of the uniform and wavy falling film in the bare tube was higher than experimental result for $Rd_{t}<100$. The absorption performance showed the maximum at the wavy film by the insert device(spring).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.272-277
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• 2003

This paper reports the fluid flow and heat transfer around a module cooled by forced air flow generated by a piezoelectric(PZT) cooling fan. A flexible PZT fan with distortion in a fluid transport system of comparatively simple structure which was mounted on a PCB in a parallel-plate channel($450{\times}80{\times}700mm^3$) accelerates surrounding fluid locally. Input voltages of 20-100V and a resonance frequency of 23Hz were used to vibrate the cooling fan. Input power to the module was 4W. The cooling effect using a PZT fan was larger than that of free convection. Fluid flow around the module were visualized by using PIV system. The temperature distribution around heated module were visualized by using liquid crystal film(LCF). We found that the flow type was y-shaped and the cooling effect was increased by the wake generated by a piezoelectric cooling fan.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.601-604
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• 2010

본 연구는 과산화수소와 케로신을 추진제로 하는 액체로켓엔진에 막냉각 링을 장착하여 막냉각 효과에 관한 연구를 수행하였다. 막냉각제의 유량 및 냉각장치 형상에 따른 열유속을 계산하기 위하여 축방향으로 열전대를 장착하여 온도를 측정하였다. 냉각제 유량은 총 추진제 유량의 0~20%의 유량으로 선정하여 실험을 수행하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.168-172
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• 2008

추진제 유량 변화와 분사기 배열에 따른 특성속도를 연구하기 위해 축소형 연소기를 이용하여 연소시험을 수행하였다. 그 결과 유사한 압력과 혼합비 조건에서 효과적인 비 단위 면적당 유량 범위가 존재함을 알 수 있었고 최외곽 분사기로부터 막 냉각이 적용된 연소실 벽면까지의 거리 증가는 연소실 내 저 혼합비 영역을 증가시키고 특성속도를 저감시키는 기능을 하는 것으로 해석결과 나타났다. 즉, 이 2가지 설계요소는 주어진 연소압력에서 액체로켓엔진 연소기의 성능을 향상시킬 수 있는 중요한 인자임을 확인하였다.

• 한국추진공학회지
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• 제6권2호
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• pp.9-17
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• 2002

난류분무 연소해석을 위한 수치해석 코드가 개발되었다. 복잡한 형상을 다루기 위하여 일반좌표계에서 이산화되었고 낮은 마하수 유동에 대한 수렴성을 증가시키기 위하여 예조건화기법과 고유치 재규격화기법이 도입되었다. 코트의 정확성은 캐비티 유동과 평면노즐에서 검증되었다. 액체로켓 엔진의 막냉각효과가 분무연소해석에 의하여 분석되었다. 막냉각은 연소효율에 부정적인 영향을 보였다. 연소실 벽면에서 막냉각효과는 연료가 많은 지역형성에 증진됨을 보여주었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 추계 학술대회논문집
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• pp.108-113
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• 1998

A numerical investigation for the flow, heat and mass transfer characteristics of the grooved evaporating tube with the films flowing down on both the inside and outside tube walls has been carried out. The condensation occurs along the outside wall while the evaporation takes place at the free surface of the inside film. The 3-D transport equations for momentum and energy are solved by using the FVM(Finite Volume Method). The free surface shape is tracked by the moving grid technique satisfying the SCL(Space Conservation Rule). Due to the secondary motion of the fluid, the film thins at the crest, while thickens at the valley. The velocity and temperature fields as well as the amounts of the condensed and evaporated mass have been successfully predicted for various operating conditions and groove shapes.