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http://dx.doi.org/10.3744/SNAK.2012.49.5.440

Large Eddy Simulation of Flow around Twisted Offshore Structure with Drag Reduction and Vortex Suppression  

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.)
Publication Information
Journal of the Society of Naval Architects of Korea / v.49, no.5, 2012 , pp. 440-446 More about this Journal
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.
Keywords
Twisted cylinder; Large eddy simulation; Vortex suppression; Drag reduction;
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