• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.3
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• pp.194-201
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• 2003

During the operation, fatigue failures and cracks of duct plate due to excessive duct vibration occurred in a fan-duct system of fossil fueled boilers. We measured static pressure variation (pressure pulsation) in the outlet, and also measured vibration at the outlet duct of a centrifugal fan. It was found that strong pressure pulsation caused by the inlet vortex occurred in inlet vane of centrifugal fan in the middle range of vane opening. Thus, excessive duct vibration is caused by strong pressure pulsation. In this Paper, it is shown that the frequency and amplitude of pressure pulsation depend mainly on vane opening and are compared with duct vibration. Also, effective solution for reducing pressure pulsation and vibration are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.2985-2992
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• 2015

In this study, the characteristics of heat transfer and pressure drop was theoretically analyzed by changing longitudinal pitch, bump phase, location of vortex generator about the staggered tube banks by applying SST (Shear Stress Transport) turbulence model of ANSYS FLUENT v.14. Before carrying out CFD (Computational Fluid Dynamics) analysis, It is presumed that the boundary condition is the tube surface temperature of 363 K, the inlet air temperature of 313 K and the inlet air velocity of 5-10 m/s. The results indicated that the heat transfer coefficient is not affected by the longitudinal pitch and the bump phase of circle type was more appropriate than serrated type in the characteristics of heat transfer and pressure drop. Additionally, in case of vortex generator location, the heat transfer characteristics showed that forward location of tube was more favorable 4.6% than backward location.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.301-307
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• 2011

Turbo blowers are mainly used in refuse collection systems. We discuss blower performance in relation to the angle of the inlet vane installed at the upstream of the blower. The flow characteristics of the components are analyzed by three-dimensional Navier-Stokes analysis and compared to experimental results. A two-stage serially connected turbo blower is introduced to analyze the performance experimentally. Throughout the experimental measurements and the numerical simulation, the distorted inlet velocity generated in the small vane angle reduces the performance of the blower, because of the local leading-edge separation and the resulting non-uniform blade loading. We also perform a detailed flow analysis using the results obtained in the numerical simulation.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.116-121
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• 2000

During the operation, fatigue failures and cracks of duct plate due to excessive duct vibration occurred in the fan-duct systems of fossil fueled boilers. We measured static pressure variation(pressure pulsation) in the outlet, and also measured vibration at the outlet duct of a centrifugal fan. It was found that strong pressure Pulsation caused by the inlet vortex occurred in inlet vane of centrifugal fan in the middle range of vane opening. Thus, excessive duct vibration is caused by strong pressure pulsation. In this paper, it is shown that the frequency and amplitude of pressure pulsation depend mainly on vane opening and are compared with duct vibration. Also, effective solution for reducing pressure pulsation and vibration are presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.82-87
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• 2000

During the operation, fatigue failures and cracks of duct plate due to excessive duct vibration occurred in the fan-duct systems of fossil fueled boilers. We measured static pressure variation(pressure pulsation) in the outlet, and also measured vibration at the outlet duct of a centrifugal fan. It was found that strong pressure pulsation caused by the inlet vortex occurred in inlet vane of centrifugal fan in the middle range of vane opening. Thus, excessive duct vibration is caused by strong pressure pulsation. In this paper, it is shown that the frequency and amplitude of pressure pulsation depend mainly on vane opening and are compared with duct vibration. Also, effective solution for reducing pressure pulsation and vibration are presented.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.615-624
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• 2014

The fin-tube heat exchanger being used for industrial boiler, radiator, refrigerator has been conducted in various studies to improve it's performance. In this study, the characteristics of heat transfer and pressure drop was theoretically analyzed according to longitudinal pitch, location of vortex generator, bump phase and number of the tube surface about the plain fin-tube heat exchanger. The boundary condition for the CFD (Computational Fluid Dynamics) analysis applied with the SST (Shear Stress Transport) turbulence model assumed as the tube surface temperature of 333 K, the inlet air temperature of 423-438 K and the inlet air velocity of 1.5~2.1 m/s. The analysis results indicated that the heat transfer coefficient is not affected highly by the longitudinal pitch, and the heat transfer characteristics was more favorable when the vortex generator was located in front of the tube. Also the bump phase of the tube surface indicated that circle type was more appropriate than serrated type and triangle type in the characteristics of heat transfer and pressure drop, and the sixteen's bump phase of circle type was most favorable.