Computational Fluid Dynamic Analysis of the External Rotor Supporting the Design of a Tidal Kinetic Turbine Prototype

The purpose of this paper is to ascertain the reliability of a zero-dimensional approach, aimed to design a double rotor kinetic turbine prototype, by means of computational fluid dynamic analysis. The interaction between the flow and the blade of the turbine prototype external rotor is evaluated. The calculation is carried out by a three-dimensional analysis using the commercial code FLUENT 15.0. In the present work, the Reynolds Averaged Navier-Stokes approach is used, with the two-equation Realizable k-epsilon turbulence model. The blades profile is a NACA 4412 interacting with flow at an attack angle of 4°, which is kept constant along the blade height. The estimation of the forces acting on the blades allows a more accurate evaluation of the blade lift coefficient, which is useful to design the blades geometry and to compute the power coefficient, previously estimated by the traditional mono-dimensional approach.