A novel wake energy reuse method to optimize the layout for Savonius-type vertical axis wind turbines

The long wake of a wind turbine has a significant impact on the performance of downstream turbines. Under the inspiration of migrating geese flying in a V or I formation to save energy, a novel wake energy reuse method is proposed to optimize the layout for Savonius-type vertical axis wind turbines (S-VAWT). VAWT wakes include a series of high speed and energy zones. On both sides of the upstream turbine, 7×16 transient two-dimensional numerical simulations are performed with Fluent to investigate wake structure, interaction effect and power coefficients (C_p) of downstream turbines. Based on Kriging Method, a response surface model (Surrogate model) is created to describe the relationship between the optimization objective C_pand layout positions. Finally, particle swarm optimization algorithm is applied to find the optimal relative layout position (5.25 m, −2.18 m) of the downstream turbine. The optimal position is located in the periodic high speed zone of the wake on the advancing blade side. And the optimal position is suitable for multi-turbines in a large wind farm. The optimization results show that C_pof downstream turbines at optimal layout position is significantly increased from 0.2477 to 0.3044 (22.89% higher).