• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.245-250
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• 1999

In order to design micro-fan appropriately, flow chacracteristics and mechanics should be carefully considered. The present work concerns with design procedure for a micro-fan using NACA(National Advisory Committee for Aeronautics) airfoil series. The generation of fan profiles is carried out automatically by defining related parameters, which is also converted to CAD/CAM data automatically. The optimal parting surface for the mold of micro-fan is also calculated by analyzing the geometric data numerically. As a consequence, the high capacity micro-fan can be developed successfully with a high-quality and an improved efficiency.

• 한국유체기계학회 논문집
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• 제13권6호
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• pp.25-29
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• 2010

In this paper, a numerical study has been carried out to investigate the influence of silencer design variables on the performance of a jet fan. In order to achieve an optimum jet fan design and to explain the interactions between the different geometric configurations in the jet fan, three-dimensional computational fluid dynamics and the Design of Experiments method have been applied. Two geometric variables, i.e., cap size and silencer length, were employed to improve the performance of the jet fan. The objective functions of the jet fan are defined as the effective velocity and total efficiency at the operating condition. Based on the results of computational analyses, the flow characteristics were discussed. The effect of silencer with a specific roughness on the performance was also discussed.

• 한국기계가공학회지
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• 제13권4호
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• pp.113-120
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• 2014

To ventilate indoor spaces, axial single-blade fans are widely used in various areas, such as schools, houses, offices, and restaurants. Recently, axial single-blade fans were developed to realize energy efficiency and noise reduction improvements. Here, an experimental study of the air flow characteristics of an axial dual-blade fan is conducted. The characteristics of the axial dual-blade fan were tested via an air flow analysis and with prototypes. For the performance of the fan, the flow rate, power consumption, and noise were evaluated. The result showed that the axial dual-blade fan uses less power and produces less noise in comparison with an axial single-blade fan.

• 대한기계학회논문집B
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• 제35권10호
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• pp.1067-1073
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• 2011

본 연구에서는 생활폐기물 관로이송 설비에 사용되고 있는 원심송풍기의 성능향상을 위해 임펠러날개 압력면과 부압면 측에 스플리터를 각각 설치하고, 스플리터의 코드길이 변화에 따른 성능특성을 삼차원 나비어-스톡스 방정식을 이용한 수치해석으로 분석하였다. 수치해석을 통한 기초연구를 바탕으로 날개 부압면측에서 발생하는 역류현상을 억제할 수 있는 스플리터의 익간설치를 고려하였으며, 주요설계 변수로는 코드길이를 설정하였다. 이를 통해 날개 부압면 측에 설치한 스플리터의 코드길이가 길어질수록 원심송풍기 압력 및 효율특성이 설계유량 조건 뿐만 아니라 유량증가에 따라 향상됨을 알수 있었다. 설계유량 조건에서 스플리터 부착 원심송풍기에 의해 효율 및 압력은 기존대비 각각 4% 및 18% 향상되었다.

• 동력기계공학회지
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• 제17권3호
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• pp.35-43
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• 2013

Generally, the chassis of an indoor RAC is composed of a rear-guider and a stabilizer. The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of the chassis of an indoor RAC. The purpose of this paper is to select the optimum design factors through the aerodynamic performance of a cross-flow fan. The design factors are the leading angle of a rear-guider (${\theta}_1$), a stabilizer setup angle(${\theta}_2$), a rear-guider clearance(${\epsilon}_1$), and a stabilizer clearance(${\epsilon}_2$), respectively. As a result, the optimum design factors of an indoor RAC can be presented as a combination of ${\theta}_1=33^{\circ}$, ${\theta}_2=55^{\circ}$, ${\epsilon}_1=6{\sim}8mm$, and ${\epsilon}_2=7mm$ through the analysis of a static pressure coefficient and a static pressure efficiency.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.104-106
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• 2003

In recent years for propulsion of cooling fan in cars are more used electrical motors than the engine direct coupled type. But the electrical motor which is now used has the brush and the commutator. Because of the brush and the commutator the electrical motor has short life time, low efficiency and mechanical- electrical noise. Therefore it is tried to develope brushless dc motor. The motor is located in the hot air from the radiator. The motor temperature increases high and the increasing of the motor temperature rolls big in its character. The cooling fan motor has relative small in size and input voltage is low. For 300 w output power must be the current of the motor high which causes high copper loss. In this paper will be tested and analysed characteristics of a dc motor which is now used for cooling fan and a BLDC motor will be designed with same character of the brushed motor and with considering of improvement of the efficiency. After design the motor should be analysed and tested.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.615-618
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• 2002

Turbo-fan for ceiling cassette type air conditioner doesn't operate in general volute. It is operated by porous material, heat exchanger. Heat exchanger increases resistance of air conditioning system and disturbs exit-flow of impeller. Therefore it has some influences on impeller capacity. In this study, we want to how that influence of exchanger on impeller capacity for ceiling cassette type air conditioner. To research, we made circular case that didn't have asymmetric part unlike rectangular case. With and without heat exchanger we measured total pressure and static pressure of impeller and three-dimensional rear flow field From the result, a turbo fan , installed in the 35mm back of fan and operated in heat exchanger, experienced $2{\%}{\~}5{\%}$% total pressure loss over all flow rate. With heat exchanger impeller efficiency decrease as flow rate decrease when flow rate coefficient was below 0.18. Especially when flow rate coefficient was below 0.12, there was $20{\%}{\~}30{\%}$ decrease of impeller efficiency.

• International Journal of Air-Conditioning and Refrigeration
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• 제17권2호
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• pp.68-73
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• 2009

In this paper, a numerical study has been carried out to investigate the influence of volute geometries on the performance of a sirocco fan. In order to achieve an optimum volute design and explain the interactions between the different geometric configurations in the volute system, three-dimensional computational fluid dynamics and the 'design of experiment' method have been applied. Several geometric parameters, such as the volute expansion angle, the cut-off position and the bell mouth shape, are employed to improve efficiency and performance. $2^k$ factorial designs were performed to screen the most influential parameters and interactions, and showed that the cut-off position and the bell mouth shape are the most significant parameters. The optimum design was selected as a result of the response surface methodology, and effects of these parameters and their interactions were presented. From the results of computational analyses and experimental data, the performance and efficiency of the sirocco fan were successfully improved. Also, detailed effects of geometric variables of the volute system on the fan performance were discussed.

• 한국컴퓨터정보학회논문지
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• 제19권2호
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• pp.161-171
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• 2014

본 논문에서는 CFDRC 사의 상용 CFD 소프트웨어인 CFD-ACE+로 전산유체역학 기법을 적용하여 수치 해석을 수행하여 배연탈황 설비에서 Induced Draft Fan(I.D.Fan) 출구부터 Booster Up Fan(B.U.Fan) 입구까지 난류 유동장과 연소 유동 문제를 모사하여 배기가스 계통 설비의 유동 특성을 해석하였다. 배기가스가 I.D.Fan 출구 ~ B.U.Fan 입구 구간을 적정속도로 균일하게 유동하여 B.U.Fan로 균일하게 유입되도록 하며 압력손실이 적게 발생하도록 설계기준 보일러 부하와 최대연속 정격유량의 보일러 부하에서 이 구간의 안내깃을 검토하였다. 검토한 결과에 대해 CFD 해석을 수행하여 I.D.Fan 출구에서 안내깃을 제거하고 B.U.Fan 입구 전에 안내깃을 보강할 수 있도록 설계를 변경하였다. 배기가스 계통에 변경된 설계를 적용하여 수치모사한 결과에서 배연탈황 설비 내부의 배기가스 압력손실이 줄어들고 유속과 유선이 균일하게 유동할 수 있어 배연탈황 시스템의 효율이 향상한 것을 확인하였다.

• 동력기계공학회지
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• 제17권1호
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• pp.58-63
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• 2013

The aerodynamic performance of double inlet sirocco fan is strongly dependent upon the design factors of impeller and scroll. In this paper, the change of scroll size was adopted to investigate the aerodynamic performances of double inlet sirocco fan and indoor PAC. Especially, a scroll expansion angle and a cut-off clearance ratio were considered to change the scroll size. In addition, the installation depth between double inlet sirocco fan and indoor PAC was considered. As a result, the total pressure efficiency of double inlet sirocco fan shows about 62%~73% according to the change of scroll expansion angles. Moreover, the flowrate performance of indoor PAC is the best at the condition of a scroll expansion angle of 8°, an installation depth of 15 mm and a cut-off clearance ratio of 8%.