Spacing Effects in Guided Vertical‐Axis Wind Turbine Arrays for Highway Energy Harvesting Under Multi‐Vehicle Wake Conditions

Abstract

ABSTRACT Highway‐induced airflow generated by passing vehicles represents an underutilized source of localized renewable energy that can be harvested using vertical‐axis wind turbines (VAWTs). While prior studies have demonstrated the feasibility of single‐turbine configurations, the aerodynamic interaction between vehicle wakes and multi‐turbine arrays—particularly the role of inter‐turbine spacing—remains insufficiently understood. In this study, two‐dimensional unsteady Reynolds‐averaged Navier–Stokes (URANS) simulations coupled with the SST k–ω turbulence model are employed to investigate the performance of guided elliptical Savonius‐type VAWT arrays operating under multi‐vehicle traffic conditions. Three‐turbine arrays are examined at normalized inter‐turbine spacings from S/D = 3 to 14, together with an additional phase‐aligned reference case at S/D = 30.114. The results reveal a strong non‐linear dependence of array‐level energy extraction on turbine spacing. Among the investigated configurations, the highest total energy capture is achieved at a spacing of 12 m (12D), yielding a total extracted energy of 697.34 J and representing a 68% increase relative to the most compact configuration. Smaller spacings are characterized by severe wake interference between turbines, whereas larger spacings exhibit progressive dissipation of vehicle‐induced flow structures despite near‐complete velocity recovery. Turbine 1 shows limited sensitivity to spacing, with an energy variation of approximately 14%, whereas Turbines 2 and 3 exhibit substantially greater variations of approximately 87% and more than 140%, respectively. The inclusion of guide vanes further enhances total energy extraction by approximately 80–120% across the investigated spacing range. These findings highlight the importance of coordinated inter‐turbine spacing and flow‐guiding strategies in maximizing energy harvesting from vehicle‐induced wakes and provide practical design guidance for the deployment of guided VAWT arrays in highway environments.