Numerical simulation of a floating body in multible degrees of freedom

Computational results for a floating body representing a single cylinder of the Manchester Bobber are compared with measured data from physical tank tests concerning the survivability of this wave energy converter in extreme waves. The float is connected to a counterweight via a pulley system, which is represented by additional forces and restricted degrees of motion in the computational approach. Two setups are discussed. In the first the float is restricted to move in vertical direction only. The second experiment also includes the horizontal displacement. The computations use a Navier-Stokes solver. The equations are discretised using a Finite Volume approach and solved for both water and air employing a Volume of Fluid method and a high resolution interface capturing scheme. For this challenging case, which also includes the inertia of the counterweight, rather than the motion of an independent floating body, the displacements of the float are presented and shown to be in reasonable agreement with the experiments.