Abstract: Experimental investigation is required to obtain the nondimensional coefficients that characterize the performance of new wind turbines and marine energy extracting devices, such as tidal turbines. However, data acquired from scaled models tested in tunnel facilities suffers from wall blockage and therefore, corrections must be applied to properly predict the performance of the full-sized rotor.
Analytical expressions based on the axial momentum theory and correlating thrust coefficient to an equivalent free stream velocity have traditionally been used to correct power coefficients obtained experimentally. For small models, accurate force measurement is very difficult requiring a new post processing methodology when thrust data is not avail able.
A methodology is presented in this paper that uses the velocity field data at the rotor plane, obtained from PIV measurements and CFD simulations, to account for blockage without the requirement for thrust data. A correction curve correlating axial induction factor and power coefficient is obtained and will be utilized for correction in future experiment testing.
