• 유체기계공업학회:학술대회논문집
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• 1998.02a
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• pp.63-72
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• 1998

This study Is on the performance prediction and design of sirocco fan. Slip coefficient is very important factor for the performance analysis of centrifugal-type fan. Because generally used slip coefficient equations of backward curved centrifugal fan are not appropriate for forward curved sirocco fan, in this study a proper slip coefficient equation for sirocco fan is suggested. Using this equation performance prediction program for sirocco fan is composed and also included the total noise prediction that include turbulent noise at the fan Inlet and boundary layer noise. A comparison between the values obtained from performance prediction program and experimental values shows that the program predicts the sirocco fan performance in a practical rate.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.1
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• pp.142-149
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• 1995

Axial fans are very useful cooling devices being widely used in many electric and industrial machinery. However those are often accompanying annoying noise. Many efforts have been devoted in order to reduce the fan noise. In this study, the procedure was devided into two major parts in considering effects of design parameters of axial fan concerned with noise ; the fan theory and the Fukano's fan noise study. By using the fan theory we defined stagger angle, camber angle, blade inlet and outlet angle for studying low noise fan. Then the effects of such angles on the flow rate and static pressure were investigated. By using the Fukano's fan noise theory, the relations of the chord length, the rotational speed and the number of blades vs. fan noise are investigated.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.789-794
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• 2013

In this study, the temperature, heat emission per unit time, and thermal stress or deformation of a radiator fan made of polyethylene or aluminum are analyzed for investigating its strength durability. Heat transfer in the case of the aluminum radiator fan is better than that in the case of the polyethylene radiator fan. Further, heat emission in the case of the aluminum fan is poorer than that in the case of the polyethylene fan. Moreover, because the thermal deformation of aluminum is much smaller than that of polyethylene, the thermal durability of the aluminum fan is better than that of the polyethylene fan. In an open space in front of the radiator and the closed space of the engine behind it, the thermal cooling effect of the polyethylene fan is better than that of the aluminum fan. Further, since polyethylene is lighter in weight than aluminum, polyethylene, as a nonmetallic plastic, is more suitable as a material of an automotive radiator. However, because of the higher strength durability of the aluminum fan, it is better than the polyethylene fan under high-temperature conditions or in the case of a complex pipe.

• The KSFM Journal of Fluid Machinery
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• v.2 no.3 s.4
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• pp.7-16
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• 1999

The flow angle at the inlet and exit of a rotor or stator is an important design parameter involved in the design a fan blade. Flow angles along the radial direction for 3-D stacking are calculated using two kinds of vortex methods, i.e. free vortex method and forced vortex method. The performance test shows that a fan designed by the free vortex method is more efficient than a fan designed by the forced vortex method. As a reference, an imported fan is tested. Even though the straightner of the imported fan is used for the comparison test, the difference of efficiency between the imported fan and the fan designed by the free vortex method is negligible. The noise of the fan designed by the free vortex method is less than that of the imported fan. A bellmouth installed at the fan inlet improved the fan efficiency more than $10\%$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.143-149
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• 2009

Recently, according to the tendency to the more comfortable automobile, the improvement of performance of the cooling fan is required. The performance of cooling fan is affected by many peripheral parts, such as radiator, condenser, engine block and etc. Therefore, it is important to consider the effect of peripheral components on the fan performance in design and analysis stages. In this paper, the performance of automobile cooling fan is investigated experimentally by using the large capacity fan tester based on the ASHRAE and the AMCA standards. In particular, the various spacing between cooling fan and engine block are considered to obtain the effect of engine block. An empirical relation between the fan flow rate and the spacing was proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.935-938
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• 2007

In suction nozzle of a vacuum cleaner, where flow-induced noise is generated mainly by flow resistance, several ideas to reduce noise are investigated. To increase fan performance, blade number is optimized and a centrifugal fan is replaced by a cross-flow fan, In addition, gear ratio of fan to drum brush is changed. It is found that fan performance is increased by adopting these methods. Next, the blade height of the fan is decreased to reduce sound pressure level, which causes inevitably decrease in fan performance. Eventually, flow-induced noise is reduced by 6.3 dBA in its overall level with the fan performance maintained.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.10
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• pp.735-741
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• 2007

An axial F.R.P. fan model for cooling tower is developed. The fan is designed using the equations for one dimensional inviscid flow through the fan blade. Fan shape is swept forward with a parabolic function. Calculations of the three dimensional turbulent flow around the fan are carried out to investigate performance of the fan. Data of the total pressure rise and hydraulic efficiency can be obtained for the various setting angles. Calculated values of the total pressure rise and hydraulic efficiency at the design point are less than those of the design specification. The prototype of the F.R.P. fan is made by laminating of the fiberglass and epoxy resins on the mold of fan shape.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.967-972
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• 2001

An axial fan design code, called iDesignFan$^{TM}$, was developed. In this code, three major loss models were used to predicted the aerodynamic performance of a fan. The overall sound pressure level, predicted from steady blade loading, is also used as an input parameter from the third loop of the designing process to acquire most silent fan for the given aerodynamic performance parameters. With this kind of inverse design concept used in this code, the period of designing a fan, which has given aerodynamic performance with minimal acoustic noise, is significantly shortened. The experimental results of a prototype fan, designed by this code, showed that aerodynamic and acoustic performance of an axial fan is reasonably well predicted. Thus, one can design/develop an axial fan in a short time by using the code.e.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.196-201
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• 2003

Axial fans are widely used for automotive engine cooling device due to their ability to produce high flow rate to keep engine cool. At the same time, the noise generated by these fans causes one of the most serious problems. Especially, engine cooling fan noise in idle condition of a car is noticeable. Therefore, the high efficient and low-noise fan is seriously needed. When a new fan system is designed, system resistance and non-uniform inflow are the key factors to get the high performance and low noise fan system. In this study, experimental study on the fan and system was carried out and brought a successful result of performance and noise from a designed fan. And through the modification of the fan system, the fan produced more flow rate and became less noisy.