Viscous numerical examination of hydrodynamic forces on a submerged horizontal circular cylinder undergoing forced oscillation

As a classical topic,the hydrodynamic forces on a submerged horizontal cylinder undergoing forced oscillation have been widely studied based on potential flow theory.However,the fluid viscosity and the flow rotation may play an important role when the oscillation amplitude of the circular cylinder is large,and large discrepancy will occur between the potential flow simulation and the experimental results.This study focuses on the study of hydrodynamic forces on a submerged horizontal circular cylinder undergoing forced oscillation by means of a viscous fluid numerical wave tank(NWT)model.The accuracy of the numerical model is validated against available experimental data.The comparisons between the hydrodynamic forces on the circular cylinder predicted by the viscous fluid model and the potential flow model are conducted to show the viscous effects on the hydrodynamic forces.By the study on the flow fields,the mechanism of the viscous effects is explained by the vortex effect.The basic reason for the difference between the results based on the viscous fluid theory and the potential flow theory is revealed by analyzing the force components.