Viscous Forces Acting on a Horizontal Circular Cylinder in Waves and a Steady Current

Abstract

It was found by Chaplin and the authors that the wave forces acting on cylinders horizontally submerged in regular and irregular waves dramatically decrease with increasing Kc number in very low Kc number region (1<Kc<3) due to vortex shedding. In the present paper, the effect of the current over a circular cylinder on the reduction of the wave forces is experimentally and theoretioally investigated in regular waves. The experimental results of the force measurements show that the inertia forces and drag forces acting on the cylinder are significantly affected by the current, direction and speed. The vortex shedding pattern is also investigated through simulations by the discrete vortex method and flow visualizations.