The secondary load cycle of a bottom-mounted circular cylinder at different Keulgan-Carpenter numbers and Froude numbers

Abstract

The influences of the Keulgan-Carpenter number (KC) and Froude number (Fr) on the Secondary Load Cycle (SLC) on a bottom-mounted circular cylinder are comprehensively investigated using computational fluid dynamics simulations by OpenFOAM. The volume of fluid method is used to simulate the wave surface, and the shear stress transportation k-ω turbulence model is adopted for turbulence modelling. The sensitivity of the inline force to grid refinement is checked, and the numerical simulation accuracy is validated by the experimental results. The development of SLC is found to be closely related to the downstream vortex shedding, which induces the reduction of the wall pressure and thus the inline force. The studied ranges of KC and Fr are (11.01, 20.26) and (0.167, 0.534), respectively. It reveals that KC and Fr significantly affect the magnitude of SLC and the 3rd and 4th-order harmonic components dominate the SLC.