Performance Study of Vertical-Axis Wind Turbine Blades

Abstract

This study presents a combined theoretical and computational performance analysis of a Vertical Axis Wind Turbine (VAWT) blade using CATIA V5 for 3D geometric modelling and ANSYS Fluent for Computational Fluid Dynamics (CFD) simulation with the SST k-ω turbulence model. Theoretical calculations were performed for inlet wind velocities of 3, 6, 9, 12, and 15 m/s using VAWT design parameters: rotor diameter D = 0.474 m, blade height H = 0.428 m, chord C = 0.300 m, and a single blade (N = 1), yielding a swept area S = 0.203 m² and solidity σ = 1.266. Theoretical results show that the available wind power increases cubically from 3.36 W at 3 m/s to 419.37 W at 15 m/s, while the tip speed ratio (TSR) decreases from 0.413 to 0.083, causing the power coefficient (Cp) to drop sharply from 0.608 to 0.005 owing to the fixed blade tip speed of 1.24 m/s. CFD simulations on a mesh of 385,726 elements confirm that the aerodynamic force on the turbine increases 25-fold, from 13.117 N at 3 m/s to 328.044 N at 15 m/s, while static pressure rises from 10.7 Pa to 154 Pa and turbulent kinetic energy grows from 0.428 to 27.3 m²/s². Velocity magnitude, static pressure, and velocity vector contours at all five wind speeds confirm high-pressure stagnation on windward blade faces, suction zones on leeward faces, and progressive wake development downstream. A strong agreement is observed between the theoretical and CFD trends, validating the computational model. The findings establish that this high-solidity, fixed-pitch VAWT configuration is most efficient at low wind speeds and highlight the need for variable-speed operation or blade pitch optimisation to sustain high Cp across a wider wind speed range.