• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1424-1429
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• 2004

To seek the fan operating point on a cooling system with fans, it is very important to determine the system impedance and it has been usually examined with the fan tester(wind tunnel) based on ASHRAE standard and AMCA standard. This leads to a large investment in time and cost, because it could not be executed until the system is made actually. Therefore it is necessary to predict the system impedance curve through numerical analysis so that we could reduce the measurement effort. This paper presents how the system impedance curve (pressure drop curve) is computed by CFD in substitute for experiment. In reverse order to the experimental principle of the fan tester, pressure difference was adopted first as inlet and outlet boundary conditions of the system and then flow rate was calculated.

• 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.

• The KSFM Journal of Fluid Machinery
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• v.13 no.6
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• pp.71-76
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• 2010

This study has investigated numerically and experimentally the flow characteristic of air-cooling fan for transmission oil cooler in the large-size diesel engine. Impellers of cooler were composed of eight normal-scale and eight small-scale blades in the zig-zag pattern. In order to increase the discharge pressure of cooling fan, turbo type of fan blade is proposed in the impeller for transmission oil cooler. The fluidic performance of cooling fan has been estimated numerically by using the commercial code and experimentally carried out with reference on AMCA Standard 210-99. As a result, it is confirmed that the numerical result for performance curve is in good agreement with experimental data.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1167-1171
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• 2008

The flow and thermal performance of the skiving and louver fin type heat sinks for the cooling system of the small LED projector were experimentally evaluated. A small fan tester based on AMCA standards was used to control and measure the air flow rate into the heat sink. Three heat blocks were used to simulate the heat and light sources(red, green and blue) of the small LED projector. We measured the pressure drop, temperatures and input power at the specific air flow rate and discussed those results. As a result, it is found that the louver fin type heat sink has higher pressure drop and lower thermal resistance than the skiving type. From the comparison of the temperature of the heat block between skiving and louver fin type, the louver fin type heat sink was found to be more suitable for cooling the high power heat source than skiving type. The thermal performance of the fan-sink(louver fin type) system was discussed with the picture taken by a thermal video.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.225-230
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• 2006

The overall performance and local flow fields of the fan, heat sink, and fan-sink were experimentally and numerically studied to investigate the flow characteristics of a fan-sink. The flow resistance of the heat sink was measured by small fan tester based on AMCA standards and compared with the CFD results to select available cooling fan for the fan-sink. The nonuniform velocity profile behind the fan outlet was shown by the flow visualization. The effects of nonuniform velocities on the performance of heat sink were discussed. To validate the commercial CFD code CFX-5.6, the predicted performance curve was compared with that of fan testing. The local flow fields of the fan-sink were analyzed by CFD results. MFR (multiple frame of reference) was used as a computational model combining rotating fan and stationary heat sink. Through the CFD results of the fan-sink, the flow patterns behind the fan outlet influenced the flow resistance and overall performance of the heat sink.