Effects of Dimples as Vortex Cavities on the Aerodynamic Performance of Darrieus Vertical Axis Wind Turbine

Document Type : Research Paper

Authors
Yuewen Huang 1
Lidong Zhang 1
Changpeng Song 1
Guoqiang Tong 2
Yuze Zhao 3
Tieliu Jiang 1
Xin Meng 4
1 School of Energy and Power Engineering, Northeast Electric Power University, No. 169, Changchun Road Sub-district, Jilin City, Jilin Province, 132012, China
2 School of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Jiangjun Road No.29, Nanjing City, 211106, China
3 School of Electrical Automation and Information Engineering, Tianjin University, No. 92, Weijin Road, Nankai District, Tianjin City, 300072, China
4 Huaneng Jilin Power Generation CO, LTD., Xinghuo Road No.399, High-tech Development Zone, Changchun City,130012, China
10.22055/jacm.2025.48524.5295
Abstract
This paper investigates the aerodynamic performance enhancement of a Straight-Bladed Vertical Axis Wind Turbine (VAWT) through dimple optimization. This study employs Orthogonal Experimental Design (OED), a classical Design of Experiments (DoE) methodology, to systematically analyze dimple parameters. Initially, three key single-dimple parameters (diameter, position, depth) were investigated, followed by an extended Dual-dimple configuration incorporating six parameters (x/c, d1, l1, d2, l2, s). The OED approach achieves optimization of these multi-factor, multi-level systems with minimal computational cost by scientifically selecting representative combinations from full factorial experiments. Numerical simulations using the Transition SST turbulence model demonstrated that the optimal Dual-dimple design improved the pressure coefficient (Cpe) by 114.9% and the Cp of the optimal Dual-dimple airfoil is 0.1227 for the numerical simulation at a Tip Speed Ratio (TSR) of 3. The position x/c of dimple 1, with an Fvalue of 2.729, was identified as the most influential parameter, exceeding the significance threshold of 2.25. The design effectively delayed dynamic stall and suppressed boundary layer separation, though performance gains diminished with additional dimples or higher TSR values. These findings provide valuable insights for optimizing VAWT blade design through surface modifications.
Keywords
Wind turbine
Dimple
OED
Dynamic stall
Numerical simulation
Subjects

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Journal of Applied and Computational Mechanics
Volume 12, Issue 3
Summer 2026
Pages 866-878