• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.3
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• pp.41-49
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• 1996

One of the typically simple structures in protected horticulture is the rain shelter, which is widely applied in summer regardless of its poor ventilation. To evaluate ventilation performance of rain shelters, the ventilation rate as well as inside temperature of one conventional and two improved rain shelters were predicted and compared under various wind speeds and irradiations. More accurate model in which the inside space of rain shelter was subdivided into three parts considering the crops grown, was developed. The ventilation rate of each opening and the general direction of air flow in the rain shelter can be predicted by the model. The ventilation rates as well as inside temperatures of each rain shelter obtained by the model and the actual measurement, proved that the ventilation performance of improved rain shelters were superior to that of conventional one.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.625-627
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• 2016

본 논문은 EDISON CFD의 전처리기, eMEGA를 이용하여 격자를 생성하고, 2차원 정렬 격자 기반 비압축성 해석자를 이용하여 유동해석을 진행한 뒤 후처리기, eDAVA를 통해 유동선을 그려 블라인드 장착에 따른 실내 공기 순환에 대한 연구 내용을 담고 있다. 본 연구는 시중에 판매중인 사생활 보호용 블라인드를 포함, 여러 블라인드의 장착 여부에 따라 실내 내부 공기 순환의 양상을 확인하고 실제로 블라인드 장착 시 실내환기에 어떤 영향을 주는지 유동 선을 통해 확인해 보았다. 블라인드 미장착시, 실내 전체적으로 공기가 고루 순환되는 모습을 보였으며, 블라인드 장착 시 대체로 블라인드 형태에 따라 유동이 이동하는 것을 볼 수 있었다. 본 연구는 사생활 보호와 환기 효율성의 관점에서의 소비자 선택권에 영향을 미치는 효과를 가져 올 것으로 보인다.

• Tunnel and Underground Space
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• v.6 no.1
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• pp.64-68
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• 1996

Analyzed in this paper is fluid flow in the region near the exhaust and blower ports of the ventilation ducts inside a vehicle tunnel. Theoretical analysis shows that prediction of the energy loss in this region is important for designing the ventilation system. A finite-difference numerical model for the two-dimensional turbulent flow field was used to obtain the flow solution as well as the energy loss. It was shown that the blower-nozzle angle ($\beta$) had an important role in establishing both the pressure gradient and the energy loss, while the effect of the distance between two ports on them was not so significant.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.5
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• pp.379-385
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• 2007

In the present study, ventilation flow in the Janggyeongpan-Jeon at Haein temple in case of building rearrangement has been investigated numerically. To achieve more accurate results, detailed shapes such as buildings and the window grills are modeled and tree canopy model is adopted to account for the effect of trees in the computation. Wind velocities as boundary condition are taken from meteorological statistical data. The numerical results show that ventilation flow distributions at Janggyeongpan-Jeon in case of building rearrangement are nearly similar to those before rearrangement.

• KIEAE Journal
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• v.7 no.4
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• pp.51-56
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• 2007

This study focuses on developing natural ventilation system which is able to satisfy the good indoor air quality and air speed. The natural ventilation system developed in this study is for double window façade and it has two operation modes for summer and winter. Operational sections of the devices have been analyzed by CFD simulation to calculate discharge coefficients of openings and estimated indoor air speed. For the analysis of the appropriate installation area ratio for each room and the optimum installation area, TRNFLOW simulation has been used. As the results, we could see that the natural ventilation system can provide the similar pollutant removal performance to 0.7 ACH of mechanical ventilation with appropriate installation area and installation area ratio.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1995.10a
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• pp.93-96
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• 1995

비가림 시설은 대표적인 간이시설로써 시공이 간편하며 강우차단 효과에 의한 생산성 향상이 기대되는 등 경제성 높기 때문에 하절기 재배에 많이 이용된다. 본 연구에서는 다양한 비가림 시설(관행형태 및 재량형태)의 형태별 효율성 평가를 위하여 적정 외부 풍속 및 일사량 조건에 대하여 각 시설의 환기율 및 실내온도 등을 포함한 환경해석을 실시하였다. 또한 시설내의 공간을 재배중인 작물의 형태에 따라 몇 개의 공간으로 구분하여 시설내의 환기저항을 고려한 시설의 환기량 및 실내온도 예측이 가능한 모델을 사용함으로써 보다 정확한 비가림 시설의 효율성 검토를 목적으로 하였다. (중략)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.3
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• pp.201-207
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• 2011

Total heat recovery type ventilators that are connected to each room with ducts are mainly installed in Korea, but they raise concern over duct pollution. In this study, indoor environments made by thin line type ventilators installed in dwelling units of apartment houses are investigated by CFD. Results show the case that thin line type ventilators installed in each room-including kitchens-make the best indoor environment that maintains air velocity at under 0.25m/s, and evenly distributes the age of air in all areas.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.7
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• pp.567-574
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• 2002

In the present study, ventilation flow rates and pressure rises through a road tunnel are simulated numerically using CFD with the various conditions such as roughness height, swirl angle of jet fan, entrance and exit effect and hub to tip ratio. By using a modified wall function, friction factor can be predicted under 10％ of error with respect to the Moody chart for the circular pipe flow and 15％, for the present tunnel. For more precise design, the effects of the swirl angle and hub to tip ratio of jet fan, which is not included in the theoretical equation of pressure rise by jet fan are necessary to be considered.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.123-126
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• 2010

터널내에 설치되는 제트팬은 비상시에는 연기와 같은 유독가스를 제거하는데 사용되며 평상시에는 장대터널에 있어서 차량에 의해 발생한 오염공기를 제거하는 중요한 역할을 한다. 파량의 피스톤효과에 의해서 일부 제거되기는 하나 1km이상의 장대터널에서는 반드시 필요로 한다. 이러한 제트팬의 효율적인 환기 및 제연설계를 위하여 CFD해석과 더불어 모형실험을 실시함으로서 터널내에 소실되는 에너지를 정량화하고 그 원인 파악과 함께 효율적인 환기설계를 위한 연구이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1111-1116
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• 2011

Heat exchangers have been used for the automotive, HVAC systems, and other various industrial facilities, so the market is very wide. In general, high-efficiency heat exchangers with louver fins are used in the dust-free environment while heat exchangers with wavy fins are used for dusty environment such as construction site, etc. In this study, numerical analysis has been performed for typical heat exchangers, used as oil coolers or fuel coolers, with dual cell model that can handle different grids for the air-side and oil-side of heat exchangers. First wind tunnel tests were conducted to obtain one-dimensional thermal performance data of heat exchangers. Then, heat release rates with varying air flows were numerically predicted using the three-dimensional dual-cell model. The model can greatly enhance the accuracy of thermal design since it includes the effects of nonuniformity of air flows across heat exchangers.