Study of the wake characteristics and turbines configuration of a hydrokinetic farm in an Amazonian river using experimental data and CFD tools

Abstract

Hydrokinetic energy generation is a renewable source that captures kinetic energy from river or tidal currents. Little physical construction is required, and environmental impacts are reduced. The identification of potential projects and definition of turbine arrangement to consider the wake dissipation generated by the flow on the rotor are two extremely important points for successful implantation of hydrokinetic farms. The present study presents a methodology for evaluating the length of the hydrokinetic rotor wakes in natural channels through the use of computational fluid dynamics techniques and the actuator disk model. These techniques were applied in this study on a portion of the Brazilian Amazon river with real measured data on velocity, curvature and geometry in the field. The wake length obtained was between 7 and 9 diameters, varying according to the operation point of the turbine. A study of the hydrokinetic arrangement for the three turbines was also carried out and an electrical power of 18.3 kW was obtained. The outcome and results of the study provided insight on hydrokinetic turbine wakes in rivers which may aid in the development of future studies, thus resulting in a greater diffusion of hydrokinetic power plants.