Sensitivity and Aerodynamic Analysis of a Darrieus Wind Turbine Using Different Geometric Parameters

Resumo

Considering the demand for renewable energy, this work has the objective of contributing to the
development of Small-Scale Darrieus Vertical Axis Wind Turbine that can be employed in decentralized electrical
generation through computational fluid dynamics, operating at a low tip speed ratio (TSR). A 2D numerical
modeling is performed with unsteady-state and turbulent flow. Geometric parameters analyzed are profile camber

(m), camber position (p), profile thickness (t), chord (c) and pitch angle (β), the first three being based on NACA-
4 digit parameterization. A sensitivity analysis using the Smoothing Spline ANOVA algorithm is conducted to

predict the influence of each parameter on the power coefficient ( Cp

̅̅̅) of the turbine. Two Designs of Experiments
(DoE) were created with 100 and 192 possible configurations of the Darrieus turbine, so it was possible to evaluate
which parameters and interaction of them have the most influence on Cp

̅̅̅. The main finds showed that the pitch

angle (β) contribution on Cp

̅̅̅ is the highest among others (69%). An analysis considering only the geometry of the
blades profile showed its influence on the flow through the turbine. Finally, an increase in aerodynamic efficiency
of Darrieus VAWT is the main responsible for increasing Cp
̅̅̅.