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http://dx.doi.org/10.5762/KAIS.2019.20.4.613

A Study on Flow Characteristic due to the Periodic Velocity Fluctuation of Upstream at Single Tube  

Ha, Ji-Soo (Department of Mechanical & Automotive Engineering, Keimyung University)
Publication Information
Journal of the Korea Academia-Industrial cooperation Society / v.20, no.4, 2019 , pp. 613-618 More about this Journal
Abstract
The flow-induced vibration in a heat exchanger may cause the damage to piping. Therefore, it is necessary to establish the flow induced vibration characteristics for the structural stability of a heat exchanger. The purpose of this study was to compare the generation, development, and separation characteristics of a vortex around a circular tube with respect to time when the flow velocity of the inlet was fluctuating constantly and periodically. The time characteristics of lift and drag and the PSD characteristics were also investigated. In the case of a constant inlet flow velocity, the well-known Kalman vorticity distribution was shown. The vortex generation, growth, and separation were also observed alternately at the upper and lower sides of the tube. In the case of periodic inlet flow velocity, the vortex occurred simultaneously in the upper and lower sides of the tube. In the case of constant inlet flow velocity, the magnitude of the lift PSD was 500 times larger than that of drag. The frequency was 31.15 Hz and that of drag was doubled at 62.3 Hz. In case of a periodic inlet flow velocity, the PSD of the drag was approximately 500 times larger than that of lift. The frequency was 15.57 Hz, which was the same as the inlet-flow velocity frequency. In addition, the frequency of lift was 31.15 Hz, which was the same Karman vortex frequency.
Keywords
Flow Induced Vibration; Lift; Drag; Power Spectral Density; Periodic Inlet Velocity; Karman Vortex;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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