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http://dx.doi.org/10.3795/KSME-B.2002.26.6.850

A Numerical Study on the Flow Development around a Rotating Square-Sectioned U-Bend(II) - Turbulent Flow -  

Lee, Gong-Hee (포항공과대학교 대학원 기계공학과)
Baek, Je-Hyun (포항공과대학교 기계공학과)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.26, no.6, 2002 , pp. 850-858 More about this Journal
Abstract
The present study investigates in detail the combined effects of the Coriolis force and centrifugal force on the development of turbulent flows in a square-sectioned U-bend rotating about an axis parallel to the center of bend curvature. When a viscous fluid flows through a curved region of U-bend, two types of secondary flow occur. One is caused by the Coriolis force due to the rotation of U-bend and the other by the centrifugal force due to the curvature of U-bend. For positive rotation, where the rotation is in the same direction as that of the main flow, both the Coriolis force and the centrifugal force act radially outwards. Therefore, the flow structure is qualitatively similar to that observed in a stationary curved duct. On the other hand, under negative rotation, where these two forces act in opposite direction, more complex flow fields can be observed depending on the relative magnitudes of the forces. Under the condition that the value of Rossby number and curvature ratio is large, the flow field in a rotating U-bend can be represented by two dimensionless parameters : $K_{TC}$ =Re $\sfrac{1}{4}$√λand a body force ratio F=λ/Ro. Here, $K_{TC}$ has the same dynamical meaning as $K_{TC}$ =Re√λ for laminar flow.
Keywords
Secondary Flow; Coriolis Force; Centrifugal Force; Duct Flow; Turbulent Flow; Developing Flow;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
연도 인용수 순위
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