• The Korean Journal of Community Living Science
• /
• v.24 no.3
• /
• pp.391-397
• /
• 2013

This study was conducted to define the characteristics of the fan according to the bed depth of rough rice for the silo used in South Korea. In this study, the characteristics like air flow resistance and air flow rate of the fan were investigated for an independent blowing system with 1 fan and the serial blowing system with 2 fans. In the experiment, the depth of rough rice was determined by 0, 1, 2, 3.2 and 4.5 m for an independent blowing system and the depth of rough rice was 4.5 m for the serial blowing system. The air flow resistances of the blowing fan and the suction fan in an independent blowing system were 55 mmAq and 88 mmAq respectively. In addition, the air flow resistance of the serial blowing system was 61% lower than the blowing fan and 28% lower than the suction fan of the independent blowing system. The air flow rates of the blowing fan and the suction fan in the serial blowing system were 516 $m^3/min$, 570 $m^3/min$, respectively. The former was 22% higher than the blowing fan while the latter was 29% higher than the suction fan in the independence blowing system. In other words, the serial blowing system was superior to the independent blowing system in blowing characteristics because the air flow rate was lower and air flow resistance was higher than the independent blowing system. However, the fan power consumption of the serial blowing system was more than 100% comparing with the independent blowing system.

• The KSFM Journal of Fluid Machinery
• /
• v.14 no.4
• /
• pp.19-24
• /
• 2011

An experimental study was conducted to examine the effectiveness of a suction-blowing fan that could not only remove polluted air by suction but also create the air-curtain by blowing. In order to create the air-curtain, rotors were installed on the surface of the shroud. These blows fresh air into the polluted region. The fresh air is spouted backward 45o on the basis of the axial direction using a double-ducted bellmouth. In the same suction operating condition, the suction region was extended by increasing the blowing velocity. However, the increasing rate of suction region was reduced when the blowing velocity was increased steadily. Thus, an efficient blowing velocity should be determined depending on the suction operating condition. In addition, the blowing requires additional input power. In a fixed suction operating condition, the input power was linearly increased in proportion to the blowing flowrate. When the suction-blowing fan was operated in the same input power as the suction fan, the suction region was increased more than 30% based on the 0.6m/sec velocity.

• Journal of the Semiconductor & Display Technology
• /
• v.19 no.4
• /
• pp.51-58
• /
• 2020

Many types of optical plastic films are essential in optoelectronics display unit fabrication and it is important to develop high precision laser cutting methods of optical films with extremely low level of film surface contamination by fume particles. This study investigates the effects of suction and blowing air motions with air flow misalignment in removing fume particles from laser cut line by employing random particle trajectory simulation and probabilistic particle generation model. The computational results show fume particle dispersion behaviors on optical film under suction and blowing air flow conditions. It is found that suction air flow motion is more advantageous to blowing air motion in reducing film surface contamination outside designated target margin from laser cut line. While air flow misalignment adversely affects particle dispersion in blowing air flows, its effects become much more complicated in suction air flows by showing different particle dispersion patterns around laser cut line. It is required to have more careful air flow alignment in fume particle removal under suction air flow conditions.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.77-82
• /
• 2000

Parametric study fur the cooling characteristic investigation of a notebook PC mounted with heat spreader has been numerically performed. Two oases of air-blowing and air-exhaust at inlet were tested. The cooling effect on Parameters such an, velocities of air-blowing and air-exhaust, materials of heat spreader, and CPU powers were simulated for two cases. Cooling performance in the case of air-blowing was better than the case of air-exhaust.

• Journal of the Korean Society of Industry Convergence
• /
• v.3 no.3
• /
• pp.245-250
• /
• 2000

This study was carried out to investigate blowing performance for blowing type in space heater. This paper present that power requirement, static pressure, total pressure and static pressure efficiency were increased in proportion to air flow rate. And in the Korean space heater, side ward blowing type was effected than downward blowing type.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.303-306
• /
• 2002

Liquid atomization by means of a spinning cup is widely used as a device for combustion, in cooling and spray drying. In this study, the blowing type rotary atomizer was experimental carried out the investigations on the characteristics of the blowing type rotary atomizer which is an air flow energy of blower instead of an electric motor most commonly used to a driven energy. The analysis on the rotary cup speed, air velocity with the blower conditions was performed and also the drop size was measured using LDPA. It was tried to analyzed on air-nozzle size and liquid flowrate as the result. It was found that the increase of the relative velocity between liquid and air improve significantly atomization liquid, and decrease of the liquid flowrate improved the maximum drop size though the mean drop size is really the same.

• International Journal of Aeronautical and Space Sciences
• /
• v.9 no.1
• /
• pp.111-120
• /
• 2008

A particle image velocimetry (PIV) technique was employed to investigate the effects of blowing jet on the flow characteristics over stationary and pitch-oscillating airfoils. The Reynolds number was $7.84{\times}10^5$ based on the chord length. It was found that for stationary airfoil cases, continuous and pulsating blowing jets successfully reduced separated wake region at high angles of attack. A comparison study of two different types of jet blowing indicated that pulsating jet is more effective than continuous jet for flow separation control. Pulsating leading-edge blowing postpones flow separation and increased stall angle of attack by $2^{\circ}{\sim}3^{\circ}$. For pitch-oscillating airfoil cases, the PIV results showed that blowing jet efficiently delays the separation onset point during pitch-up stroke, whereas it does not prevent flow separation during pitch-down stroke, even at angles of attack smaller than static ones.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.6
• /
• pp.766-775
• /
• 2001

Parametric study to investigate the cooling performance of a notebook PC mounted with heat spreader has been numerically performed. Two cases of air-blowing and air-exhaust at inlet were tested. The cooling effect on parameters such as, inlet velocities in the cases of air-blowing and air-exhaust, materials of heat spreader, and CPU powers were simulated for two cases. Cooling performance in the case of air-blowing was better than the case of air-exhaust.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.21 no.7
• /
• pp.417-423
• /
• 2009

Air curtains are widely used for gates of shopping mall, warehouse, cold stores and refrigerated display cabinets. The purpose of the air curtain is to reduce the infiltration of outdoor air and heat loss from the air conditioning space to ambient air. Design data for the air curtain given by previous researchers do not mention the influence of wind speed. Thus, this paper presents a performance of single jet air curtain in heating space when the wind blows toward the opening space of the building. A numerical simulation is used to study the influence of various parameters on the efficiency of the downward-blowing air curtain device which is installed inside of the wall above the door. The performance of the air curtain is evaluated by sealing efficiency which provides the assessment of the energy savings. A new safety factor is also proposed for determination of air curtain jet velocity under the various wind conditions.

• International Journal of Safety
• /
• v.2 no.1
• /
• pp.34-38
• /
• 2003

The lower and upper flash points of the flammable binary system, butylacetate+2-propanol were measured by air blowing tester. The shape of the concentration-temperature region of flash depended on the components of the mixture in solution. The experimental data were compared with the values calculated by the reduced model under an ideal solution assumption and the flash point-prediction models based on Van Laar equation. Good qualitative agreement was obtained with these models. The prediction results of these models can thus be applied to incorporate inherently safer design for chemical process, such as the determination of the safe storage conditions for flammable solutions.