• 유체기계공업학회:학술대회논문집
• /
• 2006.08a
• /
• pp.213-216
• /
• 2006

This paper was a study about noise reduction through flow stabilization in duct using experimental method and numerical analysis at the same time. To determine the fan's type three kinds of fans(axial fan, centrifugal fan, and axial fan with centrifugal type blades) was examined to investigate the suitability for in-line duct. As a result, under the equal number of rotation 2000 RPM, performance of an axial fan with centrifugal type blades was the most superior by 55dBA at 4.3CMM among other fans. After this, analyzed the results of the numerical analysis to find out the optimum design of pitch angle such as $0^{\circ}$, $10^{\circ}$, $15^{\circ}$ and $20^{\circ}$. The intensity of turbulence was low when pitch angle was $15^{\circ}$ and air volume became peak by 5.08 CMM. It was observed that axis component of velocity increased gradually when pitch angle increased from $0^{\circ}$ to $20^{\circ}$, and embodied noise reduction and improvement of air flow rate through flow stabilization.

• International Journal of Fluid Machinery and Systems
• /
• v.6 no.1
• /
• pp.25-32
• /
• 2013

Data centers have been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling small-sized fans; high pressure and large flow rate small-sized fan, are used for servers in the data centers and there is a strong demand to increase power of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of high power cooling fans to meet the demand for high power. There is a limitation of space for servers and geometrical restriction for cooling fans because spokes to support fan motors, electrical power cables and so on should be installed in the cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance to achieve high performance of the cooling fans. In the present paper, the performance and the flow condition of the high power contra-rotating small-sized axial fan with a 40mm square casing are shown by experimental and numerical results. Furthermore, influence of the geometrical shape of the small-sized cooling fan on the internal flow condition is clarified and design guideline to improve the performance is discussed.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.4
• /
• pp.151-158
• /
• 2005

An important component of a cooling tower is an axial fan, and there happens distortion in its shape which brings significant loss of efficiency. In this paper, a surface profile measuring system for large size axial fan of cooling towers is developed. A laser sensor is used as a measuring device and aluminum profiles and stepping motors are engaged into the system as frame structure and driving devices respectively. The measuring data are compared to the design data to compute the distortion of the axial fans. Two types of errors, axial and twist errors, are used to represent the precision of axial fan distortion. Genetic algorithm is used to solve the optimization problem during computing the precision. Results are displayed three dimensionally in a solid-modeler as well as 2-D drawings to help users find it with ease.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.8
• /
• pp.1164-1169
• /
• 2008

The miniaturization of the Air Handling Unit (AHU) has become an actual need because of the restriction of the using space on the vessel. In modern AHU’s construction, in which the fan section is at the end part of the ship, it’s very difficult to select a suitable capacity of evaporators, because the fan motor emits heat. Thus, the AHU structure has been changed as the fan section has been set before the cooling coil to get temperature values similar to the designed amount. Also, the air guider is installed in order to maintain equal air distribution after it passed the fan section. So, it is possible for air to equally pass the cooling coil. It is investigated three different geometries to find the best performance. Also, It is compared with the numerical and experimental results. The study found the case 3 gives the best results. The results of this study show the possible application of the new design.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.8
• /
• pp.994-1000
• /
• 2011

In this study, the piezoelectric fan cooling system is investigated. In order to find the proper geometry and configuration, the numerical model for the flow field and heat transfer investigation is used. A simplified nonlinear deformation model is employed for transient solutions of a piezoelectric fan with the dynamic mesh and user defined function capability. The results show that the cooling is most effective when the length of a piezoelectric fan is 5 cm and the cooling plate is 3 cm. The results can be used to develop a new design method of heat sink for piezoelectric fans.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1998.10a
• /
• pp.262-268
• /
• 1998

This study were performed to find the cooling effect and to provide design data during summer season. for the Pad ＆ Fan system of Venlo type greenhouse. The temperature and humidity variation along the greenhouse width and wind velocity in the greenhouse were surveyed. Also, the influence of shading on the cooling effect were analyzed. While Pad ＆ Fan system were operated, the temperature, humidity and wind velocity in greenhouse were different by the distance from the Pad and the height from the ground. The temperature difference between Pad and Fan was about 8.1$^{\circ}C$~10.4$^{\circ}C$ without shading and about 4.4$^{\circ}C$~5.5$^{\circ}C$ with shading.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03a
• /
• pp.233-238
• /
• 2008

An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and Flow Noise are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.3
• /
• pp.82-87
• /
• 2017

This study investigates thermal deformation due to fan shape of a hair dryer. In this study, thermal analysis showed that the shape of an electric fan results in lower temperature than that of a sieve frame. Among the shapes of electric fans, the temperature change decreases as the number of wings decreases. As a result of thermal deformation, model 4 (sieve frame shape) showed increased change of deformation compared to models 1, 2, and 3 (with electric fan shapes). Thus, the model 1 dryer with the sieve frame shape is shown to have the least durability among models 1, 2, 3, and 4. It is thought that the analysis results of this study can be applied to durability improvement and safer design of hair dryers.

• 한국전산유체공학회:학술대회논문집
• /
• 2004.10a
• /
• pp.69-72
• /
• 2004

The performance of the centrifugal fan in a vacuum cleaner is affected by the hydraulic loss, such as the friction loss, the recirculation loss and the impact loss etc., Those losses depend on the rotational speed of the impeller, the inlet and exit widths, the relative flow angles to the blade, the number of the blades and the geometry of the shroud and the diffuser. These parameters are complicatedly interrelated, so the experimental means in analyzing the fans are rather limited. In the present study, the flow analysis are done numerically by changing the relevant fan parameters. A commercial code, STAR-CD, is used for the calculations. It is seen from the analyses that the computational results agree well with the experimental results. The results obtained can be used for the basic design of a centrifugal fan.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.10a
• /
• pp.233-238
• /
• 2008

An alternator which converts mechanical rotating energy into electric energy is an important component of a vehicle. It operates in broad range from 3000 RPM to 18000 RPM. So, sufficient flow rate and low noise are needed in such broad operating range for a cooling fan of this alternator. In current study, the cooling fan of an alternator is developed through DFSS process and numerical analysis. In order to calculate flow rate and noise level, SC/Tetra and Flow Noise are used respectively, for a new developed fan, compared with original model, numerical result shows 3 dBA reduction and measured value shows 4 dBA reduction.