Publication

Abstract : This study numerically investigates the aerodynamic performance of a helical-bladed vertical axis wind turbine (VAWT) configured at different solidities. For this purpose, computational fluid dynamics (CFD) analysis was conducted using the Transition SST k-ω turbulence model. The performance coefficient (Cp) for 600 helical VAWT against experimental data indicates a deviation of less than 10%, confirming the reliability of the present results. An airfoil with a chord length of 225 mm and a rotor diameter of 2.7 m was used in this study. The turbine overlap ratio was maintained at unity to reduce torque ripple. The simulation results reveal that the 3-bladed turbine with a 1200 helical blade configuration outperforms the other configurations considered, achieving a maximum power coefficient of 0.325. The 5-bladed configuration exhibits improved torque ripple characteristics and show better pressure distribution on both the pressure and suction sides. The 5-bladed configuration generates higher moment at the leading edge, mid-segment, and trailing edge of the turbine blade. The influence of tip effects on helical turbine blades was assessed using segmental moment distribution and pressure contours. Wake analysis revealed that the velocity deficit decreased progressively downstream for all configurations, indicating wake recovery, with the 5-bladed turbine exhibiting the highest near-wake deficit (0.601 at Y/D = 2) compared to the 2-bladed turbine (0.259 at Y/D = 2). An increase in the blade count resulted in an increase in dynamic solidity from 0.78 to 0.89 at a constant tip speed ratio of 3.1, leading to faster wake recovery. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.