Plenary Lecture
Large Eddy Simulation of Flow over a Twisted Elliptic Cylinder at a Subcritical Reynolds Number
Professor Hyun Sik Yoon
Global Core Research Center for Ships and Offshore Plants
Pusan National University, Korea
Ε-mail: lesmodel@pusan.ac.kr
Abstract: The wavy cylinder has a sinusoidal variation in cross sectional area along the spanwise direction and the torsional cylinder has been newly designed by rotating the elliptic cross section along the spanwise direction, so that the cylinder surface has a twisted spiral pattern. For an ellipse, different eccentricities are considered to observe the effect of eccentricity on the flow fields. It guarantees the accuracy of the present numerical methods that the excellent comparisons with previous studies for the cases of a smooth circular cylinder and a wavy cylinder. The effect of surface torsion which is newly designed in here has been predicted and assessed in terms of the mean drag and root-mean-square (RMS) value of fluctuating lift in the subcritical Reynolds number range. Subsequently, the mechanisms of enhancing the aerodynamic performance and passive control of vortex-induced vibrations are also investigated by careful analysis with the flow structures. The isosurface of swirling strength has been imposed to identify the vortical structures in the turbulent wake.
Brief Biography of the Speaker: Hyun Sik Yoon holds a position of Associate Professor in Global Core Research Center for Ships and Offshore Plants at Pusan National University in the Korea. His research interests include flow control, heat and mixing enhancement, flow-structure interaction and biomimetics. He has authored over 100 publications in refereed journals and refereed proceedings of international conferences. He is also the recipient of numerous research grants from the National Science Foundation (NSF), other funding agencies as well as academic awards.