• 설비공학논문집
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• 제12권11호
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• pp.972-981
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• 2000

Comprehensive work is done for flows by an axial fan by experimental research. The present model fan is used for air handling device for out-door unit of an air conditioner in home appliance. PIV(Particle Image Velocimetry) system and wind tunnel are adopted for measurements of flows and performance evaluation, respectively. Major experimental conditions are the installation depth of a fan into a bellmouth of it. Optimal position of a fan in an inlet guide tube is observed by examination of fan-performance and flows in both upstream and downstream of the fan. Consequently, in the case of the fan inserted in half depth into the inlet tube, the efficiency of fan shows its maximum value and flow patterns is also streamlined.

• 한국CDE학회논문집
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• 제3권3호
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• pp.201-209
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• 1998

To develop timely an optimal fan, a design system and a new manufacturing process used step by step have to be integrated. A small sized optimal fan for refrigerators, that was the goal on this project, was developed by the following principal processes. All processes are technologically linked in many directions: The existing fan was measured through reverse engineering. The measured data was used for the basic source of 3D design. The performance tests were carried and used as the data for the evaluation of the existing fan. Flow analysis by FANS-3D/sup [1]/ was performed at the given information (pressure drop and flow rate) to find out the configuration of optimal fan design. The flow patterns were investigated to measure the performance of fan through numerical experiment. The grid point data obtained by the above analysis turned into 3D high efficiency fan model by using CATIA. The product was manufactured by RP process (SLS, SLA) and tested the characteristic curves of the developed fan to compare with the existing fan. The modification of fan design were all examined to see any change in performance and checked to find any deficiency in assembling the fan into a duct. After the plastics flow analysis of the injection molding cycle to ensure acceptable quality fan, an optimal mold was processed by using tool-path for the newly designed fan.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.10-13
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• 2010

The flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, jet fan is one of main ventilation facilities especially in longitudinal ventilation system of tunnel. In this study to analyze tunnel flow induced by operation of jet fan, numerical simulation has been carried out. The velocity distributions and streamlines in tunnel are examined to consider the three-dimensional characteristics of tunnel flow caused by jet fan.

• 항공우주기술
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• 제4권2호
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• pp.50-59
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• 2005

본 연구에서는 개발된 테일팬 1차 시제품의 성능시험에 대한 것이다. 한국항공우주연구원에서는 헬리콥터용 반 토오크 시스템으로 테일팬 시스템을 개발하였으며, 제작된 1차 시제품의 성능시험을 위해 테일팬 성능시험장치를 제작하였다. 테일팬 성능시험을 위해 먼저 시험장치에 대한 제작 검증용 시험을 수행하였고, 다음으로 팬블레이드와 시험장치의 고유진동수를 확인하였다. 성능 시험용 시험장치 운용회전수를 결정하기 위한 운용시험을 수행하였다. 테일기어박스(TGB)에 가속도계를 부착하여 단계적으로 회전수와 부착물들을 변화시켜가며 고유진동수와 진동 레벨을 확인하였다. 운용시험 결과로부터 테일팬 성능시험용 시험장치 운용회전수를 결정하였고, 무풍조건과 비행 조건에 따른 성능시험을 수행하였다. 측정된 데이터는 무차원화하여 분석하였고, 이 결과로 개발 시제품이 성능 요구조건을 만족시킴을 확인할 수 있었다.

• 소음진동
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• 제10권3호
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• pp.457-464
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• 2000

Vibrations of a fan are often generated by mechanical unbalance magnetic force and air flow. These vibrations depend on the design of a fan the machining accuracy of each element and assembled conditions. An experimental study is carried out to reduce the vibration and noise of an industrial fan in this paper. In order to identify the vibration sources of a fan the signal analysis and system analysis are performed, It is shown that the industrial fan studied in this paper has a natural frequency at 144 Hz and resonance occurs when the running speed of the fan is 1750 rpm. The results may be helpful to design a fan with low vibration and noise.

• International Journal of Fluid Machinery and Systems
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• 제3권1호
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• pp.39-49
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• 2010

In this paper, a numerical study has been carried out to investigate the influence of jet fan 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 DOE method have been applied. Several geometric variables, i.e., hub-tip ratio, meridional shape, rotor stagger angle, number of rotor-stator blades and stator geometry, were employed to improve the performance of the jet fan. The objective functions are defined as the exit velocity and total efficiency at the operating condition. Based on the results of computational analyses, the performance of the jet fan was significantly improved. The performance degradations when the jet fan is operated in the reverse direction are also discussed.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.386-391
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• 2009

In this study, the numerical study has carried out to analyze the factors of the efficiency decrease at backward flow situation in an axial fan with adjustable blades. The analysis is carried out the pitch angle $36^{\circ}$ on the forward flow and the pitch angle $-26^{\circ}$ on the backward flow. The numerical results show that the air flow rates of the pitch angle $36^{\circ}$ and $-26^{\circ}$ are respectively calculated to 285 CMM and 212 CMM. The results are similar to the experimental results carried out by Chang, and have made the maximum error of 10.6% when compared with the experimental results. The important reason of the fan efficiency decrease is that axial fan used for this study was designed to use for the forward flow. As the results, the pitch angle $-26^{\circ}$ has occurred the recirculation around the impeller blade, impeller cover and stator.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2597-2602
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• 2007

In this paper, the performance analysis is experimentally carried out in order to select the best cooling fan and shroud considering both cooling performance and noise reduction. 4 cooling fans have been tested in the fan tester and the real excavator. In order to obtain the performance of the cooling fans, flow capacity has been estimated by measuring flow velocity using a hot wire anemometer, and noise radiation has been also measured to estimate the fan noise. Characteristics of a box-type and a streamlined shroud have been examined by changing the immersion depth of cooling fans. Based upon the results, the best cooling fan is selected. Finally, the criterion to select the best cooling fan has been set up.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.678-683
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• 2001

The present work has carried out experimental study on a cross-flow fan system with a simplified vortex wall scroll casing. A cross-flow fan test rig was constructed to obtain pressure rise and volume flow rate for various fan operating conditions. The performance estimation is using a wind tunnel with a motor driven damper for flow rate control and flows are quantitatively visualized by light scattering system with a pulsed laser. Min focus on the visualization is finding a eccentric vortex inside a fan which is a major factor reducing fan efficiency. Comprehensive engineering data are prepared for industrial applications and show a good agreement with a prior work by experimental measurements.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.583-589
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• 2004

One of noticeable features in the cross flow fan is that a working fluid passes through impeller blade twice without distinction between the inlet and exit angles. Also, it does produce higher circumferential velocity than other types of blade at the same flow rate in accordance with the application of the forward curved shape. However, a design theory for the cross-flow fan has not yet been formed owing to an eccentric vortex, which is the remarkable characteristics, occurred in a cross-flow fan. Furthermore, the eccentric vortex, which is difficult to control of the size and position, is the important cause of performance decrease. In this study, experiments are carried out to estimate the similarity of the cross-flow fan with various scales and rotational velocity changes. Pressure coefficients to flow coefficients with various scales of the cross-flow fan are plotted to research the application of the general similarity law of the turbomachinery in the cross-flow fan with Archimedes spital, which is the important factor haying an effect on it.