Wind-Tunnel Experiments on the Interactions among a Pair/Trio of Closely Spaced Vertical-Axis Wind Turbines

To elucidate the wind-direction dependence of rotor performance in closely spaced vertical-axis wind turbines, wind-tunnel experiments were performed at a uniform velocity. In experiments, pair/trio three-dimensional printed model turbines with diameter D = 50 mm was used. The systematically by applying incremental adjustments to gap g and rotational direction each changing direction. For tandem layouts, speed downwind is 75–80% that an isolated rotor, even g/D 10. average pair, origin-symmetrical line-symmetrical distribution are observed co-rotating inverse-rotating configurations, respectively, thereby demonstrating for pair. trio configuration yields higher than any spacing under ideal bidirectional conditions. maximum should be obtained θ 0° configuration. speeds three explained via flow visualization using smoke-wire method velocity field study two-dimensional computational fluid dynamics.