Determination of increased mean drag coefficients for a cylinder vibrating at low values of Keulegan-Carpenter number

Abstract

There is an increasing demand for the development of a reliable technology for wind turbines in deepwaters.Therefore, offshore wind turbine technology is receiving great amount of attention by the research community. Nevertheless, the dynamic response prediction of the support system for offshore wind turbines is still challenging due to the nonlinear and self-regulated nature of the Vortex Induced Vibration (VIV) process. In this paper, the numerical implementation of a computational fluid dynamics-based approach for determination of increased mean drag coefficient is presented. The numerical study is conducted at low values of Keulegan-Carpenter number in order to predict the increment of drag force due to cross-flow motion. The simulation results are then compared with previously developed empirical formulations. Good agreement is observed in these comparisons.

Keywords

• computational fluid dynamics
• vortex-induced vibration
• drag coefficient; inertia coefficient
• Keulegan- Carpenter number
• cross-flow motion.
• drag coefficient
• inertia coefficient