Journal of the Society of Naval Architects of Korea (대한조선학회논문집)

The Society of Naval Architects of Korea (대한조선학회)
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Large Eddy Simulation of Flow around Twisted Offshore Structure with Drag Reduction and Vortex Suppression

와류감쇠 및 저항저감형 나선형 해양 구조물 주위 유동 LES 해석

  • Jung, Jae-Hwan (Department of Naval Architecture and Ocean Engineering, Pusan National University) ;
  • Yoon, Hyun-Sik (Global Core Research Center for Ships and Offshore Plants, Pusan National University) ;
  • Choi, Chang-Young (School of Mechanical Engineering, Pusan National University) ;
  • Chun, Ho-Hwan (Department of Naval Architecture and Ocean Engineering, Pusan National University) ;
  • Park, Dong-Woo (Maritime Research Institute, Hyundai Heavy Industries Co. Ltd.)
  • 정재환 (부산대학교 조선해양공학과) ;
  • 윤현식 (부산대학교 조선해양플랜트글로벌핵심연구센터) ;
  • 최창영 (부산대학교 기계공학부) ;
  • 전호환 (부산대학교 조선해양공학과) ;
  • 박동우 (현대중공업 선박해양연구소)
  • Received : 2012.07.16
  • Accepted : 2012.10.16
  • Published : 2012.10.20
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Abstract

A twisted cylinder has been newly designed by rotating the elliptic cross section along the spanwise direction in order to reduce the drag and vorticies in wake region. The flow around the twisted cylinder at a subcritical Reynolds number (Re) of 3000 is investigated to analyze the effect of twisted spiral pattern on the drag reduction and vortex suppression using large eddy simulation (LES). The instantaneous wake structures of the twisted cylinder are compared with those of a circular and a wavy cylinder at the same Re. The shear layer of the twisted cylinder covering the recirculation region is more elongated than that of the circular and the wavy cylinder. Successively, vortex shedding of the twisted cylinder is considerably suppressed, compared with those of the circular and the wavy cylinder. Consequently, the mean drag coefficient and the fluctuating lift of the twisted cylinder are less than those of the circular and the wavy cylinder.

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References

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