• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.181-186
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• 2002

A seismic analysis is one of crucial design procedures of an axial blower used in nuclear power Plants. The blower should be operated even in ar emergency such as an earthquake. The blower should be designed in order to stand against an earthquake. For the seismic analysis, Ive perform the modal analysis and then evaluate the required response spectrum (PRS) from the given floor response spectrum (FRS). A finite element model of the blower is established by using a commercial FEM code of ANSYS. After the finite element modeling. the natural frequencies. the mode shapes and the participation factors are obtained from the modal analysis. The PRS is acquired by a numerical approach on the basis of the principle of mode superposition. We verify the structura safety of the axial blower and confirm the validity of the present seismic analysis results.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.596-600
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• 2001

The seismic design for an axial blower is the procedure in which the required response spectrum (RRS) is computed by using the floor response spectrum (FRS). The seismic design is very important to reduce severe damages from an earthquake; therefore, the seismic design has been a great concern in engineering society. In this study, after finite element modeling is established by using Ansys, the modal data are obtained such as the natural frequencies, the participation factor, and so on. With these data, the RRS is acquired by a numerical approach. The seismic safety of the axial blower is evaluated.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.12-18
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• 2015

Recently, the development trend of turbomachinery is high capacity and high efficiency. Most of turbomachinery in the market are adopting ball bearings or air foil bearings. However, ball bearings have a limit for high speed product over $2.0{\times}10^6DN$(product of the inner diameter of the bearing in mm (D) and the maximum speed in rpm (N)). Air foil bearings have a limit for high axial load for high power products over 200~300 HP(horse power). Magnetic bearing is one of the solutions to overcome the limits of high speed and high axial load. Because magnetic bearings have no friction between the rotor and the bearings, they can reduce the load of the motor and make it possible to increase the rotating speed up to $5.0{\times}10^6DN$. Moreover, they can have high axial load capacity, because the axial load capacity of magnetic bearing depends on the capacity of the designed electromagnet. In this study, the radial and thrust magnetic bearings are designed to be applied to the 200 HP class turbo blower, and their performance was evaluated by the experiment. Based on the tests up to 26,400 rpm and 21,000 rpm under the no-load and load condition, respectively, it was verified that the magnetic bearings are stably support the rotor of the turbo blower.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.67-72
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• 2006

Blower as an air supply system is one of the most important BOP (Balance of Plant) system fur FCV(Fuel Cell Vehicle). For generating and blowing compressed air, the motor of air blower consumes maximum 25% of net power and fuel cell demands a clean air. Considering the efficiency of whole FCV, low friction lubrication of high speed rotor is needed. For the purpose of reducing electrical power and supplying clean air to Fuel cell, oil-free air foil bearings are applied at the each side of brushless motor (BLDC) as journal bearings which diameter is 50mm. The normal power of driving motor has 1.7kW with the 30,000rpm operating range and the flow rate of air has maximum 160 SCFM. The impeller of blower was adopted a mixed type of centrifugal and axial which has several advantages for variable operating condition. The performance of turbo-blower and parameters of air foil bearings was investigated analytically and experimentally. From this study, the performance of the blower was confirmed to be suitable far 80kw PEM FC.

• 한국전산유체공학회:학술대회논문집
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• 2005.04a
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• pp.25-29
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• 2005

Axial fan is used for the supplement of large amount of flows. Axial blowers show relatively high efficiency of the system. The present model of axial fan is for cooling a condenser in an air-conditioning unit that exhibits tendency toward compact size. In order to realize the compact model, the width of an axial blade should be cut down in axial distance. Main interest lies on the performance of the axial blowing system with blades having shorter chord length. One of the important design parameters for axial fan is the shape of the blades of it. Design of blades includes the cross-sectional shape and its dimension, including the chord length. We consider two types of blades; one is NACA airfoil with normal chord length and the other is with shortening chord length by $10\%$ of normal airfoil. Axial blower with the modified blades is essential for the compact model of an air-conditioner. The other design parameters are same in the two cases. Using a wind tunnel follows ASHRAE standards carries out evaluation of performance of the system. Detail of flows around the blades is prepared by velocity measurements using PIV. According to performance estimation, the axial blower with short chord blade show quite close to the performance results, including flow rate and pressure rise, of the standard one. The reason of the two similar results is that the flowpatterns depend on Reynolds number based on the chord length of a blade. In this investigation, the critical chord length is found, in which the flows near the airfoil are so unstable and the performance of the system is decreased. A series of figures is for the detail information on the flow.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.55-60
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• 2022

This study conducted the measurements of air flow rate for blower systems with experiment and numerical. A new airflow rate test method is suggested, with which it is possible to accurate measurements and calculate the air flow rate for blower systems. The blower(axial fan) is an industrial fluid machine device that supplies a large amount of air by driving an impeller with an electric motor, and it is widely used throughout the industry such as steel, power plant, chemical, semiconductor, LC D, food, and cement. The airflow from the blower is for exchanging the heat in the cooling unit or heat exchanger. The temperature of coolants and hydraulic oil primarily depends on the amount of airflow rate through the cooling package so its accurate estimation is very important. Moreover, it required a larger investment in time and cost since it could not be executed until the system is actually made. Therefore, this research is intended to examine the phenomenon of air flow pattern when testing air flow rate, suggested new test method, and show the result of the validation test.

• The KSFM Journal of Fluid Machinery
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• v.18 no.6
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• pp.71-75
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• 2015

The flow and noise characteristics of the regenerative blower are evaluated experimentally. To decrease the noise of regenerative blower at a high frequency, we arrange the impeller vanes unevenly by special formula. The uneven pitch formular consists of the combination of trigonometric function. The magnitude of degree between each vanes and the control parameters of trigonometric functions are main design parameters for the uneven pitch. The flow characteristics of even and uneven impellers are tested by the fan tester and compared each results. The efficiency of a blower is calculated by the axial power using a dynamo system. The noise property of designed impeller is measured in an anechoic room. In this study, we certify that the uneven pitch impeller is effective in the noise reduction at a high frequency.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.37-43
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• 2008

The durability test of turbo-blower for PEM fuel cell is very important process of BOP development. It is a major barrier to the commercialization of these systems for stationary and transportation power applications. Commercial viability depends on improving the durability of the air supply system to increase the reliability and to reduce the lifetime cost. In this study, turbo-blower supported by oil-free bearing is introduced as the air supply system used by 80kW proton exchange membrane fuel systems. The turbo-blower is a turbo machine which operates at high speed, so air foil bearings suit their purpose as bearing elements. The impeller of blower was adopted mixed type of centrifugal and axial. So, it has several advantages for variable operating condition. The turbo-blower test results show maximum parasitic power levels below 1.67kW with the 30,000 rpm rotating speed, the flow rate of air has maximum 163SCFM(@PR1.1). For proper application of FCV, these have to durability test. This paper describes the experiment for confirming endurance and stability of the turbo-blower for 500 hours.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.17-30
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• 2002

The design method of turbomachinery has been developed highly. But some geometric dimensions have been determined from the empirical view points. In designing the inlet outer diameter of pump impeller and the hub ratio of blower, satisfactory theoretical grounds have not been presented till now. In the paper, these points are discussed and the method of increasing pump and blower efficiencies are also discussed on the basis of experimental and computational results of flow analysis. Further, the effects of tip clearance of rotor on its efficiency and the interference of rotor and stator blade rows are discussed and some ideas to estimate their effects are presented.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.541-544
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• 2002

The turbine performance test of an axial-type turbine is carried out with various axial gap distances between the stator and rotor. The turbine is operated at the low pressure and speed, and the degree of reaction is 0.373 at the mean radius. The axial-type turbine consists of ons-stage and 3-dimensional blades. The chord length of rotor is 28.2mm and mean diameter of turbine is 257.56mm. The power of turbo-blower for input power is 30kW and mass flow rate is $340m^3/min\;at\;290mmAq$ static-pressure. The RPM and output power are controlled by a dynamometer connected directly to the turbine shaft. The axial gap distances are changed from a quarter to two times of stator axial chord length, and performance curves are obtained with 7 different axial gaps. The efficiency is dropped about $5{\%}$ of its highest value due to the variation of axial gap on the same non-dimensional mass flow rate and RPM, and experimental results show that the optimum axial gap is 1.0-1.5Cx.