Efficient clusters and patterned farms for Darrieus wind turbines

Recent studies show that interactions between Darrieus vertical axis wind turbines (VAWTs) arranged in close proximity mutually enhance the output power of individual turbines. In this paper, multi-Darrieus turbine clusters are studied for the development of efficient patterned vertical axis wind turbine farms. Numerical solutions are performed for a single Darrieus turbine, clusters of two Co- and counter-rotating turbines in parallel and in oblique configurations, and triangular three turbine clusters. The commercial CFD software FLUENT 14.5 is used for the numerical simulation. The single Darrieus turbine results are validated against experimental data. The results of the simulation of the multi-turbine clusters are used to develop an efficient triangular shaped three turbine cluster having an average power coefficient up to 30% higher than an isolated turbine. Efficient Darrieus wind turbine farms are developed using the enhanced three turbine cluster. The farms consist of multiple clusters with scaled geometrical ratios of the three turbine cluster keeping the same topology of the cluster. This resulted in patterned farms that have the same power enhancement ratio of the three turbine cluster. Numerical simulation of a farm that consist of nine turbines confirm the enhancement and the pattern progression for larger farms.