• 유체기계공업학회:학술대회논문집
• /
• 1998.02a
• /
• pp.136-143
• /
• 1998

• Proceedings of the KSME Conference
• /
• 2000.11b
• /
• pp.441-446
• /
• 2000

The experiments of the Aerodynamic characteristics of a counter-rotating axial fan were carried out. The performance tests of a single and a counter-rotating axial fan were carried out based on the Korean Standard Testing Methods for Turbo-fans and Blowers(KS B 6311). The performances of single and counter-rotating axial fans were obtained and compared with each other. The flow fields of a counter-rotating axial fan at the peak efficiency point were measured using a five-hole probe. As a result, compared with the performance of a single-rotating axial fan, that of a counter-rotating axial fan was superior. And it is confirmed that most of the swirl flow generated by the front rotor was eliminated by the rear rotor.

• The KSFM Journal of Fluid Machinery
• /
• v.13 no.6
• /
• pp.71-76
• /
• 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 Korean Society of Propulsion Engineers Conference
• /
• 2003.10a
• /
• pp.211-214
• /
• 2003

For prediction of the windmilling performance with consideration of bypass-duct loss of the twin-spool axi-centrifugal turbo-fan engine in flight condition, this study has examined the windmilling process and the physical phenomenon of the engine parts. Also, a mixing phenomenon with air passed through the bypass-duct has been analyzed. The results of the predicted windmilling performance has been compared and analyzed using the dimensional parameters.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.02a
• /
• pp.221-227
• /
• 2000

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.2
• /
• pp.201-210
• /
• 2002

Experiments were done for performance and flow characteristics of a counter-rotating axial flow fan. Performance curves of a counter-rotating axial flow fan were obtained and compared by varying the blade pitch angles. The fan characteristic curves were obtained following the Korean Standard Testing Methods for Turbo Fans and Blowers (KS B 6311). The fan flow characteristics were measured using a five-hole probe and a slanted hot-wire. The velocity profiles between the hub and tip of the fans were measured and analyzed at the peak efficiency point. The peak efficiency of the counter-rotating axial flow fan was improved about 15% respectively, compared with the single rotating axial fan. The single rotating axial flow fan showed relatively law efficiency due to the swirl velocities behind rotor exit which produced pressure losses. The counter-rotating axial flow fan showed that the swirl velocity generated by the front rotor was eliminated by the rear rotor and the associated dynamic pressure is recovered in the from of the static pressure rise.

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• pp.89-93
• /
• 2004

To numerically construct the sound fields by a plenum fan mostly found in Air-Handling Unit (AHU), the Kirchhoff-BEM approach was applied to the near-field data of a turbo fan. The scattering effects were found to be significant by the plenum box structure for high-frequency components of source. The directivity petterns and sound pressure levels were also dependent upon the helmholts number which must be considered of the design stage for sound reduction program.

• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.373-378
• /
• 2003

In this paper, build up of fan performance tester in KITECH was introduced. The fan tester was set up based on AMCA standards 210-99, ANSI/ASHRAE 51-1999 with maximum flowrate within $1000\;m^{3}/min$. Both of inlet and outlet chamber setup with multiple nozzles described in AMCA 210 were established. The development of fully automatic control and measurement system are described. With this system, the accuracy of fan performance test can be maintained through the various flowrate and the uncertainty can be reduced.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.541-547
• /
• 2000

Experiments were done for the comparison of performance and flow characteristics between a two stage axial flow fan and a counter-rotating axial flow fm. The fan performance curves were obtained by the Korean Standard Testing Methods for Turbo Fans and Blowers (KS B 6311). The fan flow characteristics were measured using a five-hole probe by the non-nulling method. Each stage of the two stage axial flow fan used for the present study has an eight bladed rotor and thirteen stator blades. The front and the rear rotor of the counter-rotating axial flow fan have eight blades each and are driven by coaxial counter rotating shafts through a gear box located between the rear rotor and the electric motor. Both of the two axial fan configurations use identical rotor blades and the same operating conditions for the one-to-one comparison of the two. Performance characteristics of the two configurations were obtained and compared by varying the blade setting angles and axial gaps between the blade rows. The passage flow fields between the hub and tip of the fans were measured and analyzed for the particular operating conditions of peak efficiency, minimum and maximum pressure coefficients.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.281-286
• /
• 2004

The vacuum cleaner motor runs on very high speed for the suction power. Specially, the motive power is provided by the impeller being rotate on very high speed. And centrifugal fan consists of the impeller, the diffuser, and the circular casing. Due to the high rotating speed or the impeller and small gap distance between the impeller and diffuser, the centrifugal fan makes very high noise level at BPF and harmonic frequencies. In order to calculate the sound pressure of centrifugal fan, the unsteady flow data is needed. And Noise cause is dividing to fluid noise by exhaust flow of fan and vibration noise by rotational vibration of vacuum cleaner fan motor. Until now, measuring method has been used to measure vibration by the accelerometer; this method has been not measured for the vibration in some parts of brush and commutator because of motor construction and 3-D vibrating mode. This paper was purposed on the accurate analysis, using laser vibration analyzer,. By using this measured data of noise cause against the difficult part in old times, we would like to use for the design of silent fan motor.