Mathematical Modeling of the New System for Capture of Wave Energy

The paper presents the mathematical modeling of the wave energy capture process. The wave energy is transformed into torque by a device composed of multiple floating cylinders, which perform oscillating motions according to the wave parameters and to the constructive elements of a new patented device.

The role of superhydrophobicity in the adhesion of a floating cylinder

Horizontal cylinders floating on liquid surfaces are mundanely observed, whose examples include the legs of aquatic arthropods and floating larvae, twigs and hairs. We study the force and energy required to lift the cylinder clear from the water surface, to evaluate the role of wettability, especially superhydrophobicity, in the adhesion of floating cylinders. We find that a drastic degree of energy saving is achieved when lifting a superhydrophobic cylinder as compared with a cylinder with moderate wettability. This can serve as a starting point to understand how the superhydrophobicity of the legs of water-walking insects help to propel them efficiently.

Attraction and repulsion of floating particles

The horizontal force that has to be applied to floating cylinders to equilibrate the capillary force is calculated for a general geometry with cylindrical symmetry and for any wetting characteristics of the cylinders. The force on a cylinder can be related to a single parameter of each of the two menisci that contact the cylinder. It is found that the force between parallel vertical plates or parallelipipeds can be repulsive if one of the contact angles is acute and the other obtuse. The force on cylinders between fixed walls is also calculated and the results suggest that it may be possible to separate floating particles with different wetting properties by placing them between two walls with different contact angles.