Abstract
This paper shows LES analysis of turbulence effects on vortex-induced oscillation of a circular cylinder. First, we discuss the accuracy of the computed results of the wake flows and pressure distribution for a stationary circular cylinder in smooth and turbulent flows as a function of Reynolds numbers. Next, the present LES method is applied to the flow around a freely-oscillating circular cylinder in smooth and turbulent flows. Turbulence effects on characteristics of the response and vortex motions around an oscillating circular cylinder are examined. Consequently, we investigated the swiching of the vortex patterns and the effect of secondary vortices on rapid phase jump, concerning the vortex formation. It is recognized that only one of two vortex patterns in lock-in range is weaken by oncoming turbulence, while another is not.
