• International Journal of Fluid Machinery and Systems
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• 제5권4호
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• pp.168-173
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• 2012

This paper presents a numerical investigation on the aerodynamic performance according to the application of splitter blades in an impeller of a centrifugal fan used for a refuse collection system. Numerical analysis of a centrifugal fan was carried out by solving three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model. A validation of numerical results was conducted by comparison with experimental data for the pressure and efficiency. From analyses of the internal flow field of the reference fan, the losses by the reverse-flows were observed in the region of the blade passage. In order to reduce these losses and enhance fan performance, two splitter blades were applied evenly between the main blades, and centrifugal impellers having the different numbers of the main blades were tested with their application. Throughout the numerical analyses of the centrifugal fan with splitter blades, it was found that the reverse-flow regions in the blade passage can be reduced by controlling the main blade numbers with splitter blades. The application of splitter blades in a centrifugal fan leads to significant improvement in the overall fan performance.

• International Journal of Fluid Machinery and Systems
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• 제7권2호
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• pp.60-67
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• 2014

In order to clarify the effect of inlet bellmouth size of semi-opened type axial fan on its performance and flow fields around rotor, fan test and flow field measurements using hotwire anemometer were carried out for 6 kinds of bellmouth size. As results of fan test, the shaft power curve hardly changed, even if the bellmouth size changed. On the other hand, the pressure-rise near best efficiency point became small with the bellmouth size decreasing. Therefore, the value of maximum efficiency became small as the bellmouth size decreased. As results of flow field measurements at fan inlet, the main flow region with large meridional velocity existed near blade tip when the bellmouth size was large. As bellmouth size became smaller, the meridional velocity at fan inlet became smaller and the one at outside of blade tip became larger. As results of flow field measurements at fan outlet, the main flow region existed near rotor hub side.

• 대한기계학회논문집B
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• 제41권3호
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• pp.211-219
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• 2017

본 연구에서는 전산유체역학 프로그램을 이용하여 순환형공기분급기 내부유동 및 입자거동을 해석하였다. 주날개 및 분급날개의 회전속도 조건을 변화시키며 이에 따른 등급분급효율, 절단입경 및 분급첨예도 변화를 예측하였다. 주날개의 회전속도를 제어함으로써, 절단입경을 증가시킬 수 있었으나, 오염토양 분급에 적용할 수 있을 정도의 정확도를 확보할 수 없었다. 반면, 분급날개의 회전속도를 증가시킴으로써, 절단입경을 감소시킬 수 있었으며, 보다 정확하게 입자를 선별할 수 있었다. 결과적으로 주날개와 분급날개를 동시에 사용할 경우, 높은 분급첨예도 결과를 보이며, 우수한 분급특성을 유지할 수 있었다.

• 한국생산제조학회지
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• 제21권2호
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• pp.259-266
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• 2012

In this study, the temperature distributions are analyzed on the air flow according to the position of fan inside computer main frame by CFD simulation. In case that ventilation hole is existed at the side of computer frame, the air with lower temperature can be circulated near CPU radiant thermal panel. In case of installation with fan at the side panel, the temperature of air flow becomes lowest. The efficiency of thermal emission at personal computer and its durability can be improved by releasing a lot of heat at air flow effectively inside computer frame according to this simulation result.

• 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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.594-597
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• 2007

The notebook system use the radial fan to cool the main chipsets which generate heat. It needs to improve cooling performance by increasing fan RPM or increasing fan volume. But the former accompanies acoustic noise problem and the latter has a limitation due to notebook height and cooling area. So this study shows fatal parameters in the fan performance view point, and optimization process with Design Of Experiment. With this result, the fan CFM increases with same size of fan and we can use it as a result of decreasing fan acoustic noise.

• International journal of advanced smart convergence
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• 제10권1호
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• pp.166-175
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• 2021

The purpose of this study is to analyze the structural relationship among fan experience, fan satisfaction, team attachment, psychological well-being, team loyalty and quality of life. Specifically, the structural equation model is analyzed for the team performance side leading to fan experience-fan satisfaction-team attachment-team loyalty and the an performance side leading to fan experience-fan satisfaction-psychological well-being-quality of life. The survey to achieve the goal of this study is a professional baseball fan. 150 pilot envestigation and 348 main envestigation were selected as the final effective samples. Data processing was done with SPSS 23 for frequency analysis, exploratory factor analysis and reliability analysis. Also, AMOS 21 was used for confirmatory factor analysis and structural equation model analysis. The results of the analysis are as follows: First, fan experience had a positive effect on the fan satisfaction. Second, fan satisfaction had a positive effect on the team attachment. Third, fan satisfaction had a positive effect on the psychological well-being. Fourth, team attachment had a positive effect on theteam loyalty. Fifth, psychological well-being had a positive effect on the quality of life.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.82-87
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• 2007

A cleaner has trouble with too much noise and power consumption. To solve these problems, the investigation for motors, which are the main component of vacuum cleaner, is required. However, it is difficult to analyze the flow by the experimental means because of the high speed of the fan rotation ranging from 30,000 rpm to 50,000 rpm. Moreover it takes much time to perform the numerical simulation for the flow. In this research, it is aimed to analyse the flow through the centrifugal fan which is believed to be a main noise source, by the computational method. The efficiency of the centrifugal fan is affected by friction loss, shock loss and so on. Those losses depend on factors like the velocity of impeller, blade shape and etc. Accordingly, the influence of the shape of impeller on the flow is investigated in this study. The computational analysis was done by changing impeller shapes. The flow around the centrifugal fan is simulated by applying the moving mesh. To verify the validity of the computation results, the air flow rate and the pressure field to the cleaner is compared with the experimental data. All simulations are performed by using commercial code SC/Tetra. The calculated results show good agreement with the experimental ones qualitatively and it is believed to be promising to use computational simulation in the improvement of the vacuum cleaner performance.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.283-286
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• 2006

This paper presents a numerical study on the overall performance and local flow characteristics of the sirocco fan. The effects of impeller and volute shape distribution on the performance of the sirocco fan were numerically studied using a commercial CFD code and a DOE (design of experiments) software. At present, our attention was focused on the relation of the results of DOE and the performance of the sirocco fan. As a main result of the optimization, the performance of the sirocco fan was successfully improved. Also, detailed effects of geometric parameter of impeller and volute in the sirocco fan were discussed.

• 설비공학논문집
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• 제26권5호
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• pp.206-211
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• 2014

The objective of the present study was to identify ventilation problems, and also to suggest new axial fan systems for the improvement of IAQ in the underground parking lots. Numerical results for air mean-velocity, local mean age, and sound power level are presented along with some of fan angles. The results showed the influence of airflow patterns on the fan performances installed in the underground parking lots. Discharge air volume is increased with the angle of the blade. And also, the main factors affecting the noise of the ventilation fan was found to be a rotational speed.