An Experimental Investigation and a Theoretical and Computational Methodology to Study an Innovative Technology for Marine Current Exploitation: the Kobold Turbine

In this paper we present a joint experimental and theoretical research on an innovative technology for marine current exploitation based on the Kobold turbine concept. In particular, a research project by INSEAN, the Italian Ship Model Basin, in collaboration with Ponte di Archimede International S.p.A. (PdA) is described. A full-scale prototype of this vertical-axis turbine has been realized by PdA and it is currently successfully operating in the Messina Strait in Italy since 2001. The experimental activity is primarily intended to provide data for the validation of the theoretical and computational methodology. Different scale model configurations of Kobold turbine has been tested at the INSEAN model basin at different sea current conditions and over a wide range of variation of operating conditions. Those data will be used as benchmark for comparison with the numerical model prediction's codes and as a source of information for the design of improved and optimized real prototypes. The theoretical activity focuses on the development of models and computational tools to describe turbine global flow-field features and to predict performance. The theoretical and computational methodology is based on a general hydrodynamics formulation valid for three-dimensional unsteady inviscid flows. Trailing vorticity dynamics and viscosity effects are taken into account through suitable modelling.