https://doi.org/10.1140/epjs/s11734-025-01818-2
Regular Article
Improving energy extraction in VAWT clusters: effect of blade count, wake synergy, and inter-turbine spacing
1
Department of Aerospace Engineering, Indian Institute of Technology Kanpur, 208016, Kanpur, India
2
IIHR-Hydroscience and Engineering, University of Iowa, 52242, Iowa City, IA, USA
3
Department of Sustainable Energy Engineering, Indian Institute of Technology Kanpur, 208016, Kanpur, India
Received:
5
May
2025
Accepted:
16
July
2025
Published online:
4
August
2025
This study investigates the performance characteristics of vertical-axis wind turbine (VAWT) clusters, with a particular focus on the influence of blade count on system efficiency. To evaluate the cluster performance across various configurations, high-fidelity numerical simulations are conducted using a coupled approach that integrates large eddy simulation (LES) with the actuator line method (ALM). The number of blades per turbine is systematically varied from two to seven, and the resulting impact on the power output of a three-turbine cluster is analyzed. The results show that, in contrast to the conventional preference for three-bladed turbines, four-bladed turbines perform better in the cluster arrangement. This improvement is attributed to enhanced kinetic energy interactions in the turbine wake, leading to more effective energy extraction across the cluster. This observation remains consistent across a range of incoming wind directions. Furthermore, the study examines the impact of turbine interspacing on cluster performance and finds that an inter-turbine spacing of 2.5 times the rotor diameter (2.5D) yields better performance than the commonly used 3D spacing. The analysis highlights that critical parameter including blade number, turbine rotational direction, and the spatial configuration within the cluster collectively contribute to the overall power coefficient of the system. These findings provide valuable insights for the design and optimization of VAWT clusters, with implications for improving the efficiency and sustainability of wind energy harvesting.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
