Influence of lateral rotor spacing on the benefits in power generated by multi-rotor configurations

Abstract

In this work, an analysis of the rotor wakes interaction for different array configurations of onshore wind turbines, has been made using CENER’s in-house aerodynamic module, called AeroVIEW. The study focuses on how the distance between rotors affects the increases in power and thrust obtained by configurations with more than one laterally aligned rotor. Two configurations of laterally aligned multi wind turbines of NREL 5-MW type, operating at 8 m/s wind speed and 9.21 rpm, have been analyzed. The first one consists of 5 wind turbines and the second one consists of 2 wind turbines. These configurations have been studied for different separation distances between the rotors hubs, between 1.1 diameters and 3 diameters. The increases obtained in power with AeroVIEW are in line to the results of high fidelity tools found in the literature. The results show a higher increment of power with lower separation distances. Moreover, this beneficial effect on the power generated, has a counterpart in the average thrust, whose increase is around half of the power increase.