An experimental and numerical study of the wake flow behind propeller hydrokinetic turbines in a triangular frame arrangement was carried out. Wind tunnel experiments were performed using a set of three small scale models with four blades horizontal axis propeller turbines. Firstly, hot wire anemometry measurements in the wake of two neighbors machines were obtained to build a mapping of velocity field in the rear cross-flow plane. The experimental results are complemented by unsteady 3D CFD simulations. The experimental and numerical mapping of the flow fields, characterize the wake interaction and its influence in the second row of turbines. Thus, a third machine is placed in a back position and a performance assessment for different runner rotation speed was carried out. An optimum position of the three machines was determined in order to propose the best arrangement of the turbines working in a staggered-row or triangular frame arrangement.
Prof. Antonio C. P. Brasil Junior
Universidade de Brasília. Laboratório de Energia e Ambiente.