Design and CFD Analysis of Multi Rotor Wind Turbines

Wind power is one of the fastest-growing renewable energy technologies, with global installed wind-generation capacity having increased by a factor of almost 75 in the past two decades. The wind turbine rotors are increasing in diameter to achieve higher power output which poses various challenges in terms of parameters such as structural costs, logistics, maintenance and manufacturing standardization. Multi Rotor Wind Turbines are one potential betterment to Single Rotor Wind turbines. The aim of this study is to compare the performance of Multi Rotor Wind Turbine to a Single Rotor Wind Turbine using Computational Methodology. A total of 8 Horizontal Axis wind turbines which vary in terms of number of rotors, the rotor diameter and the placement of rotors, have been modelled using SolidWorks®. The flow simulations are carried out on ANSYS Fluent®. It is found that a 4 Rotor configuration with rotors placed in a square formation provides an increase in power output by 35% in comparison to its Single Rotor counterpart. Analysis of wake patterns shows that wake recovery is faster in lesser diameter configurations. The drag force is also found to be low in these configurations, which is beneficial in terms of structural costs and tip losses.