• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.572-577
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• 2004

This paper presents numerical study on the performance improvement of the sirocco fan in a range hood. The performance of sirocco fan means a higher flowrate, a higher static pressure and a lower required motor power in a fixed geometry constraint. Various impeller geometric parameters, such as blade profile, blade diameter, blade thickness profile and blade exit angle, were investigated by numerically and the results were compared with each other to know the effects on the performance. In this approach, the volute geometry were fixed with the original shape. The numerical results show that the blade profile with airfoil shape and small exit blade thickness increases the performance. The blade exit angle shows optimum angle within a varied range. The efficiency of the optimized exit angle was about $10\%$ higher than the base blade exit angle and the static pressure was about $28\%$ higher at the flow coefficient 0.22.

• 보일러설비
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• s.71
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• pp.97-98
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• 1999

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.270-274
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• 2001

Fans are widely used in household electrical appliances due to their easy usage and high performance for cooling capacity. However, the noise generated by these fans causes one of serious problems. LG electronics makes the intranet software for design and analysis of fan. Axial, sirocco and centrifugal fan can be designed and analyzed by using the IFD(Intranet Based Fans Design) software. In order to calculate the aeroacoustic noise of a fan, the numerical method, which can calculate the acoustic pressure at the blade passing frequency and its higher harmonic frequencies, has been developed. To calculate the unsteady resultant force of the blade, vortex method is used. This paper shows the overview of the software and validates the accuracy of predicted noise of fan.

• The KSFM Journal of Fluid Machinery
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• v.7 no.1 s.22
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• pp.17-23
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• 2004

Aeroacoustic characteristics of sirocco fan used in Over-The-Range (OTR) has been analyzed in this paper. A microwave hood combination over the gas range is short for the OTR. The flow phenomena of the double-sided sirocco fan was analyzed numerically and experimentally by using commercial code and three dimensional PIV for flow visualization. Also, microphone array is used in order to understand acoustic characteristics of OTR. Two dimensional unsteady flow and acoustic simulation is tried to qualitatively estimate the effects of tonal noise and broadband noise on the overall sound pressure level. It is found that tonal sound is generated from the strong interaction between the impeller and cutoff while broadband sound is generated from the strong secondary flows along the scroll surface. To reduce the noise level, the V-shape cut-off was applied to improve the sound quality by reducing tonal noise. So the peak noise at BPF (Blade Passing Frequency) was almost reduced. The shape of flow-guide to suppress the secondary flow over the scroll surface was carefully checked. It is found that this affects flow pattern at the fan exit and reduces the broad band noise. Through this numerical and experimental study, the sound pressure level was lowered by 4dBA compared to that of the previous fan at the operating point.

• Journal of computational fluids engineering
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• v.13 no.4
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• pp.72-79
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• 2008

This study is to investigate the air flow around a sirocco fan which is used in a range hood. The main object of the study is to improve the flow rate of the fan by analysis of unsteady 3-dimensional incompressible flow. Overall analysis is carried out using CFD method. For this, we used a commercial code, SC/Tetra, and used a sliding mesh method to give the same condition as an actual state. First, verification of the CFD results is done by comparing the experimental data with the numerical data for the suction flow rate. It is confirmed that two results are well consistent. Then for the improvent of flow rate, the effect of shape factors such as diameter ratio of fan, geometry of case, cut-off aperture and guide angle of case exit on the suction flow rate was considered. Especially, for a new design of housing, the principle of Archimedes spiral was used. The overall analysis was applied to a new design of housing, and the result showed an increase of flow rate by 10.7%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.6
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• pp.761-768
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• 1999

This paper is studied to find the optimum condition of double-inlet Sirocco fan installed in an indoor PAC for low noise operation by the Taguchi method. The goal of this study is to obtain the best combination of each control factor which results in a desired flowrate of Sirocco fan with minimum variability. In this study, the parameter design of the Taguchi method is adopted for robust design by the dynamic characteristic analysis using orthogonal arrays and S/N ratios. The flowrate measurements are conducted by using a multiple-nozzle-type fan tester according to the orthogonal array L9($3^4$). The results of this study can be summarized as follows ; (i) The optimum condition of control factor is a set of where A is an inner to outer diameter ratio($D_1/D_2$), B is a width to outer diameter ratio($L/D_2$), C is a blade attachment angle(${\theta}$) and D is a number of blade(Z), (ii) The flowrate under the optimum condition satisfies the equation $y=0.0384{\cdot}M$ where M is a signal factor, namely number of revolution. The flowrate performance improves about 7.3% more largely as compared with the current condition, which results in about 35RPM reduction of number of revolution for the target flowrate $18.5m^3/min$, and (iii) The sensitivity analysis shows that the major factors in contribution to flowrate performance are A, B, and D ; the percentage contributions of each control factor are 44.01%(Z), 26.77%($D_1/D_2$) and 20.42%($L/D_2$).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.366.1-366
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• 2002

It is addressed that the turbulent broadband sound power from a sirocco fan can be modeled by the trailing edge noise. The trailing edge noise is usually influenced by inflow turbulence, separation, and boundary layer on the blade. The design parameters such as solidity(c/s) and stagger angle are specified to predict performance and noise level because the separation and slip velocity are strong1y affected by them along with the flow coefficient. (omitted)

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.5
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• pp.730-736
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• 2008

The purpose of this study is to find out a flow characteristics when a crossflow-fan is installed inside the computer case and to provide information about the preliminary data of cooling efficiency of CPU and a flow inside and outside of a computer case. Under the condition of operating the fan inside the experimental duct we changed the position of a installation of the slot, and the experiment measured with PIV and the results are as follows. Under the influence of the crossflow-fan installed to the air discharging side, mean velocity between 35 to 45 on the point 80 of the Slot 0.2.3 of the case increased and it influences discharging the air inside of the computer case. On the left-upper end. which isn't directly influenced by the suction-discharging fan installed inside the PC, a flow occurs caused by vortex due to the Sirocco-Fan and Slot installed on the center of the right side. We can see that a flow distribution increases when the Sirocco-Fan operates and a whirl appears stronger between the slot and the suction fan. It is thought that this phenomenon is influenced by a flow while it is on the way of entering from the suction-fan and going out to the discharging-fan.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.805-813
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• 2012

A fan is the most common air flow machinery and is being used in various different industries such as for heavy machinery, home appliances and automobile. An axial fan has blades that force air to move parallel to the shaft about which the blades rotate. This type of fan is used in a wide variety of applications, ranging from small cooling fans for electronics to the giant fans used in wind tunnels. An axial fan generating large air volume used to cool equipments, but is less efficient. A sirocco fan is a efficient device for moving air by centrifugal force and can generate high pressure. Fans that affect the performance and noise of a product are important components. It is also a time and budget consuming equipment to develop a fan through physical experiments. In order to overcome this problem, we have designed and developed a fan simulator for axial and sirocco fan's fluid analysis using supercomputer. Performance and noise prediction based on datamining without numerical analyses is also developed for the conceptual design of a fan.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.396-401
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• 2000

It is addressed that the turbulent broadband sound power from a sirocco fan can be modeled by the trailing edge noise. The trailing edge noise is usually influenced by inflow turbulence, separation, and boundary layer on the blade. The design parameters such as solidity(c/s) and stagger angle are specified to predict performance and noise level because the separation and slip velocity are strongly affected by them along with the flow coefficient. This paper reports the effects of the solidity and the stagger angle upon the trailing edge noise from the circular arc-shaped blade of sirocco fan.