• Journal of computational fluids engineering
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• v.7 no.2
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• pp.33-42
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• 2002

Numerical estimation for concentration of mono-carbon oxygen (CO) gas inside an underground parking lot with auxiliary jet fans for enhancement of ventilation is carried out by using a commercial program. Main interest lies on the diagnosis of the present ventilation system including position and selection of auxiliarly fans in addition to main suppliers and exhausts. Details of both flows and concentration of CO gas that is most important component among car exhaust gases are illustrated in this investigation and those are presented for engineering construction of an underground parking pool. Prediction data of computational work is also validated by real measurements of concentration of CO gas.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.32-38
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• 2007

The increasing demand on the comfortable working conditions in automotive part plant pushes the company to improve working environment of workers. we analyzed thermal flow of an automotive part factory by using CFX code. Internal working environment has been analyzed with/without ventilation system.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.3
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• pp.229-235
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• 1997

The comparison of radiative and convective heat transfer in a room air ventilation is investi¬gated by a numerical simulation. The room air temperature distributions with radiation are appeared more uniform than without radiation at Gr= 1460 and Re=50. The mean Nusselt number in the radiative heat transfer shows less value than convective heat transfer. The total mean Nusselt number is found Wall 1> Wall 3${\fallingdotseq}$Wall 2 7 Wall 4.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.2
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• pp.267-274
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• 2006

There are no solar loads through windows and heat transfer from outer walls of the building to the interior This study analyzes indoor air temperature and air flow distribution for the interior of buildings or vessels occupying space. Numerical method is adopted to visualize the indoor side environmental situation. that is without heat transmission to outside the building in various cooling load conditions; supply ventilation lighting. occupancy and infiltration in conditioned spaces. Reaching time of an air conditioner is predicted theoretically by cooling load variations. Theoretical modelling of the reaching time shows good agreement with experimental results.

• Journal of Environmental Science International
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• v.13 no.4
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• pp.367-376
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• 2004

In urban area, thermal pollution associated with heat island phenomena is generally regarded to make urban life uncomfortable. To overcome this urban thermal pollution problem, urban planning with consideration of urban climate, represented by the concept of urban ventilation lane, is widely practiced in many countries. In this study, the prevailing wind ventilation lane of a local winds in Daegu during the warm climate season was investigated by using surface wind data and RAMS(Reasonal Atmospheric Model System) simulation. The domain of interest is the vicinity of Daegu metropolitan city(about 900 $km^{2})$ and its horizontal scale is about 30km. The simulations were conducted under the synoptic condition of late spring with the weak gradient wind and mostly clear sky. From the numerical simulations, the following two major conclusions were obtained: (1)The major wind passages of the local circulation wind generated by radiative cooling over the mountains(Mt. Palgong and Mt. Ap) are found. The winds blow down along the valley axis over the eastern part of the Daegu area as a gravity flow during nighttime. (2)After that time, the winds blow toward the western part of Daegu through the city center. As the result, the higher temperature region appears over the western part of Daegu metropolitan area.

• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.25-30
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• 2008

A Numerical study was carried out for a propane gas pool fire in the fire test room of $2.5m{\times}2.0m{\times}2.5m$ for testing a inert gas water mist system, to investigate a possible under-ventilation in the fire test room. For the fire sizes of 60 kW and 120 kW, changes in the temperature and CO concentration with and without a window were investigated. It was confirmed that the influence of the window on the distributions of temperature and CO concentration was small in the two fire sizes, and hence the under-ventilation was not occurred in the room.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.239-249
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• 2005

Ventilation effect is analyzed for boiler building with multiple heat sources. Air flow inside the boiler building is characterized as turbulent mixed convection. Analysis methodology is set up with two different $k-{\varepsilon}$ type models (standard $k-{\varepsilon}$, RNG $k-{\varepsilon}$). Two different cases with high and low outside temperature are analyzed. In case of high outside temperature condition, mixed convection is well realized inside the boiler building. With different upper louver opening rate, air flow is also well established and proper opening rate is found to meet design limit in case of low outside temperature condition. Difference of analysis results for two different turbulence models are not significant. Therefore, analysis methodology with simple $k-{\varepsilon}$ turbulence model is found to be reliable for the boiler building ventilation analysis. However, more simplified geometrical model is desired to expand its application.

• Fire Science and Engineering
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• v.22 no.1
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• pp.61-67
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• 2008

This study is focused on the numerical predictions of heat and smoke exhaust characteristics in an underground subway station stopping a fire train. Various ventilation operating modes with the fan equipped the platform and tunnels are considered. Distributions of temperature, carbon monoxide and visibility at a height of 1.7 m(breath height) above the platform are analysed for different ventilation fan operation mode. The numerical results show that smoke and heat is rapidly removed through tunnel by operating the tunnels fans. We suggested that during evacuation of passengers is not completed, the ventilation system in the platform is activated. After completion of passenger evacuation tunnel fans are activated but the fans in the platform are stopped.

• Journal of the Korean Solar Energy Society
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• v.31 no.4
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• pp.57-65
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• 2011

This study proposes a Passive Solar Chamber System (PSCS) as a passive method for reduction of building energy consumption. Through numerical analysis, the study quantitatively analyzes system performance and aims to provide foundational data for system design. For this purpose, the study configures different system operation modes seasonally and also computes thermal and ventilation performance of the system in accordance with design factors(solar radiation, air channel height and distance). System and ventilation efficiency increases along with increase in solar radiation and air channel distance; however, as the air channel height increases, the efficiencies showed a tendency to decrease. Upon installation of PSCS, an average of $98.23W/m^2$ of heat flux was introduced in the daytime for the month of January in comparison to walls with no PSCS installed. For the month of August, natural ventilation of $56.68m^3/h$ was shown to be supplied to the room.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.411-416
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• 2006

In this paper, we performed the experimental and numerical study on the thermal comfort(TC) and indoor air quality(IAQ) in the lecture room with a different airflow rate of the ventilation system and heating system for heating season. Through the experimental results, we found out that there was considerably difference of the PMV but there was little difference of $CO_2$ concentration with a different heating system. From a numerical results, the best operating condition was that discharge airflow rate of SAC is 29 CMM and supply airflow rate of the ventilation system is 1,200 CMH from a viewpoint of TC and IAQ.