• Proceedings of the KSME Conference
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• 2007.05b
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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.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.78-82
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• 2004

The cross-flow fan which is used for air-conditioner indoor units were studied experimentally. The recent trend shows that the room air-conditioners need to be good-looking. According to the visual design concepts the intake regions of the fan can vary, which leads to the loss of the performance and the increase of the noise of the fan. In order to optimize the performance of the fan and minimize the aerodynamic noise for the system, the performance characteristics and the noise of the cross-flow fan have been investigated at the various conditions of the intake region of the unit.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.92-97
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• 2009

The performance of cooling fan is affected by many peripheral parts, such as radiator, condenser, engine block and etc. Higher power has been requested in more confined automobile engine room. Thus, cooling performance becomes very important to remove the heat generated from the automobile engine more efficiently. In this paper, the performance of cooling fan including effects of engine block is investigated by using a fan tester based on the ASHRAE and the AMCA standards. A flow rate - gap distance curves and a flow rate - engine block constant curves are obtained from this study.

• The KSFM Journal of Fluid Machinery
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• v.8 no.2 s.29
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• pp.9-15
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• 2005

This paper presents an experimental and numerical study on the overall performance and local flow characteristics of sirocco fan in a range hood. Measurement of overall performance for sirocco fans were conducted based on AMCA standard 210. The effects of flow blockages due to the motor inside the fan on the fan performance were investigated by experimentally and numerically and the results were compared with each other. The numerical and experimental results show the inlet flow blockage reduces the performance (ie. fan static pressure, design flow rate, maximum efficiency and free delivery flow rate) of fan. It is found that the blockage makes the flow field highly non-uniform through the blade and cause the efficiency decrement.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.8
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• pp.1048-1062
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• 1999

A numerical method and experiments for the aerodynamic design of high performance two-stage axial flow fans was carried out. A vortex ring element method used for the aerodynamic analysis of the propellers was extended to the fan-duct system. Fan Performance and velocity profiles at the fan inlet and outlet are compared with experimental data for the validations of numerical method. Performance test was done based on KS B 6311(testing methods for turbo-fans and blowers). The velocity profile was obtained using a 5-hole pitot tube by the non-nulling method. The two stage axial flow fan configurations for the optimal operation conditions were set by using the experimental results for the single rotating axial flow fan and the single stage axial flow fan. The single rotating axial flow fan showed relatively low efficiency due to the swirl velocities behind rotor exit which produced pressure losses. In contrast, the single stage and the two-stage axial flow fans showed performance improvements due to the swirl velocity reduction by the stator. The peak efficiency of the two stage axial flow fan was improved by 21% and 6%, compared to the single rotating axial flow fan and the single stage axial flow fan, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2215-2227
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• 1994

A multicast switch, which can provide a single uniform switching function for vastly different classes of traffic, is crucial for the successful deployment of intergrated broadband networks. In this paper, we study the call blocking probability of heterogeneous circuit emulated traffic in a multicast switch. A previous work on the analysis of homogeneous traffic, where all calls have the same fan-out, show the performance showed that the call blocking probability increases rapidly as fan out increases. We study the performance of heterogeneous traffic, which consists of calls of different fan out, and show the performance gaps between larger fan-out traffic and smaller fan-out traffic are larger than those of homogeneous traffic these results indicate the necessity of efficient resource allocation policies to improve the performance of multicast calls. We conclude the paper introducing several methods to improve the performance of multicast traffic.

• The KSFM Journal of Fluid Machinery
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• v.13 no.2
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• pp.48-53
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• 2010

A computerized design system of axial fan is developed for constructing 3-D blade geometry and predicting both aerodynamic performance and noise. The aerodynamic blading design of fan is conducted by blade angle distribution, camber line determination, airfoil thickness distribution and blade element stacking along spanwise distance. The internal flow and the aerodynamic performance of designed fan are predicted by the through-flow modeling technique with flow deviation and pressure loss correlations. Based on the predicted internal flow field and performance data, fan noise is predicted by two models for discrete frequency and broadband noise sources. The present predictions of the flow distribution, the performance and the noise level of actual fans are well agreed with measurement results.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.51-60
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• 1997

In this paper, we investigated the heating performance and the basic characteristics required for normal combustion of kerosene fan heater. And also the iso-velocity contours and the iso-temperature contours of hot gas discharged from the exit of kerosene fan heater were analyzed. The experiment was carried out with kerosene fan heater attached to the blow-down-type subsonic wind tunnel with a test section of $240mm{\times}240mm{\times}1200mm$. The purpose of this paper was to obtain the basic data for new design from conventional kerosene fan heater. Consequently it was found that (i) the pressure ratio $P_2/P_1$ had a comparatively constant value of 0.844 according to the increase of the revolution of turbo fan, (ii) the primary excess air ratio had a range of $0.84{\sim}1.11$ during normal combustion, and (iii) the heating performance of kerosene fan heater had a range of $1,494{\sim}3,852kcal/hr$.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.25-31
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• 2011

The performance of fan for engine room of ship is absolutely important when it take into consideration work efficiency, work condition, and the performance of various equipments. Fan performance test should be carried out during sea trial to satisfy owner's requirement as above mentioned. We have considered various values to affect fan test result. In here, various values are to be silencer, fan inlet shape, and arrangement of fan room. In general, the shapes of fan inlet is overall circular type because of the shapes of axial fan. So, all vessels built at SHI have been applied fan inlet of circular type. And now, in order to reduce sound of noise from supply fan, big silencer often has been installed at high value vessels. In this case, the capacity of supplied air can be insufficient due to silencer which is an obstructer about air flow. In this paper, we have studied the performance of fan through comparison between a circular shape and a square shape of fan inlet. We also compare with CFD results and experimental results.

• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.9-16
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• 2006

Performance characteristics of an axial flow fan having distorted inlet flow have been investigated using numerical analysis as well as experiment. Two kinds of hub-cap, rounded and right-angled front shape, are tested to investigate the effect of inlet flow distortion on the fan performance. Numerical solutions are validated in comparison with experimental data measured by a five-hole probe downstream of the fan rotor. It is found from the numerical results that non-uniform axial inlet velocity profile near the hub results in the change of inlet flow angle. Large recirculation flow upstream the fan rotor for the right-angled hub-cap induces a negative incidence, thus invokes separated flow on the blade surfaces and deteriorates the performance of fan rotor.