Design Procedure of an innovative turbine with rotors rotating in opposite directions for the exploitation of the tidal currents.

This work presents an innovative on-shore marine turbine. The peculiarity of this turbine is the anchoring system, consisting in a rope subject only to a tensile stress, the central deflector, responsible of the equilibrium in the horizontal plane, and the floating stabilizer, keeping the machine in vertical position. An important step in the design of the machine is the implementation of a couple of rotors instead of just one. Rotating in opposite direction they make the machine free from any torsional effects. Taking in to account the equilibrium conditions as a key point of the design, the equilibrium equations in both the horizontal and the vertical plane can be obtained. Based on the experience gained, the design procedure of the proposed turbine is described, then, a first evaluation for a pilot plant in the site of Punta Pezzo (Messina – Italy) has been carried out.