Numerical Analysis of the Dynamic Interaction between Two Closely Spaced Vertical-Axis Wind Turbines

• Published in: Energies (Basel) Vol. 14; no. 8; p. 2286
• Main Authors: Hara, Yutaka, Jodai, Yoshifumi, Okinaga, Tomoyuki, Furukawa, Masaru
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.04.2021
• Subjects: closely spaced arrangements; computational fluid dynamics; dynamic interaction; phase synchronization; vertical-axis wind turbine; wind energy
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en14082286

To investigate the optimum layouts of small vertical-axis wind turbines, a two-dimensional analysis of dynamic fluid body interaction is performed via computational fluid dynamics for a rotor pair in various configurations. The rotational speed of each turbine rotor (diameter: D = 50 mm) varies based on the equation of motion. First, the dependence of rotor performance on the gap distance (gap) between two rotors is investigated. For parallel layouts, counter-down (CD) layouts with blades moving downwind in the gap region yield a higher mean power than counter-up (CU) layouts with blades moving upwind in the gap region. CD layouts with gap/D = 0.5–1.0 yield a maximum average power that is 23% higher than that of an isolated single rotor. Assuming isotropic bidirectional wind speed, co-rotating (CO) layouts with the same rotational direction are superior to the combination of CD and CU layouts regardless of the gap distance. For tandem layouts, the inverse-rotation (IR) configuration shows an earlier wake recovery than the CO configuration. For 16-wind-direction layouts, both the IR and CO configurations indicate similar power distribution at gap/D = 2.0. For the first time, this study demonstrates the phase synchronization of two rotors via numerical simulation.