Study of the wind farm arrangements and wake characteristic using numerical simulation for crossflow wind turbine

Abstract

Among of the renewable energy sources, wind energy is the fastest growing. To achieve economic scale, the wind turbines are usually built as wind farms. There are some designs of wind farm that most of them are proposed for horizontal axis wind turbine type. However, there is no wind farm design for vertical axis wind turbine, such as crossflow wind turbine, yet. The crossflow wind turbine could be used to extract wind energy in low wind speed and has a high power coefficient. In order to be able to work perfectly, a proper arrangement of wind turbines on the wind farm should be determine to decrease wake. The objective of this research was to study the effect of the crossflow wind turbine arrangement in wind farm with 2 dimensional numerical analysis using ANSYS FLUENT CFD software. The variations of the wind farm in the study were aligned and staggered configuration, in which the distance between the turbines were 0.5D, 1D and 1.5D, where D was the turbine outer diameter. Each variation was tested at the wind speed of 2 m/s and tip speed ratio (TSR) of 0.1. The study revealed that the best arrangement of crossflow wind turbine configuration is staggered arrangement within the distance S1:S2 of 0.5D:0.5D. The wake effect in staggered arrangement doesn't disturb surrounding the crossflow wind turbine in wind farm area, because the wind is blowing in streamline flow. The appropriate distance between wind turbines would increase the power density of the wind farm. Compare to an isolated crossflow wind turbine, there is 10% increase of power density.