• 설비공학논문집
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• 제9권1호
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• pp.14-22
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• 1997

The position of propeller fan from duct inlet is one of basic parameters for the design of propeller fan. To investigate the effect of its position on fan characteristics, the inlet flow fields and relative flow angles were measured by a 5-hole pitot tube. The experimental results indicate that the ratio of radial flow introduced from propeller circumference to total inlet flow increases with the increase of propeller distance from duct inlet. When fan operates without duct, the total flow rate and the radial flow ratio are higher than those of any other positions of propeller relative to duct inlet. The radial flow ratio decreases as a flow coefficient and the propeller distance decrease. Therefore the front flow fields can be adjusted in some extent by varying the propeller distance according to a fan loading. The inlet flow angles are decreasing a little as a rotational speed and the propeller distance decrease. In the present case it was judged that the deviation angle of outlet flow became negative owing to a flow separation near a trailing edge.

• 산업기술연구
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• 제36권
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• pp.3-7
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• 2016

The change of flue gas residence time with the location of air inlet in an incinerator is analysed. An independent numerical variable is the location of air inlet and dependant is the residence time of flue gas. The mean value of turbulence energy in a primary combustion chamber is also analysed. The flow field and the distribution of turbulence energy are investigated to evaluate their influence on the residence time of flue gas and the turbulence energy. As the position of secondary air inlet approaches to the top of primary combustion chamber, the residence time of gas and the turbulence energy become longer and larger respectively.

• 한국융합학회논문지
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• 제11권5호
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• pp.159-164
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• 2020

본 연구에서는 자동차에서의 공기의 유입구에 따른 자동차 내부에서의 유동 해석을 하였다. 공기가 들어오는 유입구로서 쾌적성이 좋은 조건으로서는 유입구가 자동차의 상단 중간이나 전방위치임을 확인할 수 있었다. 차량 내부에 공기 유동의 고르게 분포가 안되는 경우는 자동차의 하단 위치가 유입구의 모든 조건들 중에서 가장 저조한 조건하다. 본 연구 결과를 통하여 탑승자의 기호나 상황에 맞게 공기의 유입이 되도록 그 유입구의 위치를 조절하므로서 자동차 내부의 상태를 쾌적하게 유지할 수 있는데 도움이 될 것이다. 본 연구의 설계 및 해석 결과는 실제적으로 자동차에서의 공기의 유입구의 위치를 조절하는 데에 효율적으로 적용할 수 있다. 자동차에서의 공기의 유입구에 따른 유동해석을 적용함으로서, 본 논문이 미적인 설계에 부합된 융합 연구라고 보여진다.

• 한국추진공학회지
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• 제3권4호
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• pp.51-57
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• 1999

Ramjet 엔진에서 Ramjet 입구의 초음속 유동에 의한 압축과정은 연소기내로 유입되는 공기의 온도를 상승시킨다. 따라서 고도와 비행조건에 따라 변하는 실제비행조건을 모사하기 위해서는 공기의 온도와 속도를 정확하게 제어할 필요가 있다. 본 연구에서는 Vitiated Air Heater를 제작하여 공기, 수소, 산소의 안을 변화시키면서 Vitiated Air Heater 연소가스(Vitiated Air)의 온도분포와 속도분포, 그리고 연소가스 성분을 측정함으로써 Vitiated Air Heater의 성능을 평가하였다. 그 결과 Ramjet 엔진의 지상실험범위에 요구되는 Ramjet 연소기 입구의 유입 속도범위(80~120 ㎧)와 온도범위(400~800 K)를 만족하였으며, 균일한 속도 및 온도분포로 대기공기와 같은 산소성분비를 가지는 Vitiated hir를 얻을 수 있었다.

• 한국포장학회지
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• 제28권3호
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• pp.211-215
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• 2022

Air distribution occupies an important position in the smart unit load container design process for agricultural products. Inner air may be uncomfortable because of its temperature, speed, direction, and volume flow rate. It doesn't matter how efficient the ventilation equipment is if the air is not distributed well. The main aim of this study was to design the inlet and outlet fan locations of smart unit load container for agricultural products. A numerical study was performed on the effects of the location of inlet air and outlet air in relation to the container cooling sources on air distribution and thermal comfort. A concept of combining inner container cooling sources with the exhaust outlet was employed in this investigation. Also, in this research, the developed CFD (Computational Fluid Dynamics) models were thoroughly validated. This system was adopted for use in container spaces, where the exhaust outlet was located. In this study, the location of the inlet was derived through CFD for a container with a size of 1,100×1,100×1,700 mm, and it was derived that the inlet was located at the center of the lower part of the container for efficient air flow. It was efficient to position the outlet through the air inlet in the center of the lower part of the container at the top of the same side.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.135-140
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• 2005

Installation of ceiling type unit is achieved by one of efforts for agreeable classroom environment embodiment along with economic growth. But research about changing the position of ceiling type unit is lacking in present. Therefore, this thesis is to study the thermal environment of 5 different position cases of ceiling type, namely Case A, B, C, D, E. Here, Case C is the case that has the position of ceiling type center of the classroom and the other 4 alternatives are 0.7 m away from the Case C according to x and z axis. In this thesis temperature distributions, air current distribution, heat amenities such as PMV of occupants are analyzed as the environmental factors. Through these factors, Case C and Case D are the better position alternatives than the alternatives of Case A, Case B and Case E because the latter cases the air current reaches directly to indoor occupants so that occupants feel chilly. This thesis has a conclusion under the condition of only one inlet air temperature and seat arrangement. But afterwards more inlet air condition and seat arrangement must be considered.

• 대한기계학회논문집
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• 제11권5호
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• pp.725-730
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• 1987

본 연구에서는 2사이클 기관의 흡입 포오트 부근의 가스 유동을 레이저 도플 러 유속계를 이용하여 측정하고 가스의 평균 속도, 속도 변동, 유속 벡터 등을 기관의 회전 속도, 실린더 헤드의 모양 및 실린더로의 흡입 속도 측정점의 위치 변화에 대하 여 비교 검토하고, 유동 특성을 고찰하였다.

• 설비공학논문집
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• 제14권12호
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• pp.1014-1022
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• 2002

This paper analyzed the characteristics of heat transfer in quadangle duct with absorber plate by solar radiation. Effects o( Reynolds number on increasing temperature at outlet for variation of absorber plate temperature were analyzed by using numerical analysis technique. And also the effects of turbulent intensity of inlet flow on increasing temperature at outlet for various duct height and effects of inlet aspect ratio of quadrangle duct and position of heating surface on the outlet temperature were analysed. As the results, Outlet temperature was greatly influenced in low Reynolds number. And the highest outlet temperature distribution appeared on the inlet aspect ratio 2 because of the buoyancy effect.

• 한국화재소방학회논문지
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• 제16권4호
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• pp.7-14
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• 2002

열원의 발열이 있는 작은 공간에서 상승기류에 의한 연기 확산의 특징에 대하여 조사하였다. 유입구와 유출구의 위치와 연기의 발생위치의 변화에 대한 3가지의 경우에 대하여 수치시뮬레이션을 이용하여 연기가 어떻게 확산되는가를 알아보았다. 좌측 상부에 유입구와 우측 하부에 유출구가 설치된 경우와 좌측 하부에 유입구, 우측 상부에 유출구가 설치된 경우는 기류속도, 공기온도 및 연기농도는 비슷한 분포를 나타냈다. 또한, 좌측 하부의 유입구와 우측 상부의 유출구인 경우 온도분포는 0∼0.3이고, 연기의 농도분포는 0.06∼0.14로 나타났다. 특히, 열원의 발열의 위치는 작은 실에 있어서 온도분포에는 영향을 미치지 않으나, 농도분포에는 영향을 미치는 것을 나타났다.

• 동력기계공학회지
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• 제10권4호
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• pp.43-49
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• 2006

Nowadays, the thermal environments of classrooms are usually adjusted by the ceiling type air-conditioning system with a temperature sensor installed on inlet of an air-conditioner. However, it is not clear that the conventional temperature sensor position is proper to satisfy both thermal comport and energy saving in summer especially. Therefore, this study is aimed at finding out the best position of the temperature sensor on the purpose of the comfort thermal environment and energy saving. The different 5 positions for the temperature sensor are supposed in this paper to analyze thermal environment by CFD. From the analysis through the CFD simulations, the best position of the temperature sensor satisfying for both comfort thermal environment and energy saving is obtained.