Investigating the Effect of Geometrical and Dynamic Parameters on the Performance of Darrieus Turbines: A Numerical Optimization Approach via QBlade Algorithm

Abstract

Increasing energy demand, rising per capita energy use, growing climate problems and other detrimental consequences of energy and environmental issues have prompted scientists and engineers to conduct more studies on the technical feasibility and efficiency of renewable energy conversion systems. Free flow (wind and hydrokinetic) turbines are one of the mostly investigated renewable energy technologies and Darrieus turbines have an exceptional place especially for smaller scale and domestic applications. Many experimental and computational studies have been provided on the performance of Darrieus turbines. However, the number of numerical studies which are more time and cost effective than computational and experimental works are quite limited in the literature. The main objective of this study is to analyze Darrieus turbines at different geometrical and dynamic configurations using numerical QBlade software. In this study, the effect of airfoil selection, thickness, number of blades, chord length, solidity and helicity are analyzed in terms of delivering higher performance at straight bladed Darrieus turbines. It has been found that NACA 0020 profile performs better relative to other symmetrical blade sections in vertical axis turbines. Better performance and wider TSR range is obtained for three bladed turbines. Also, increasing chord lengths delivered maximum power at lower tip speed ratio (TSR) ranges. This study is expected contribute site-dependent Darrieus turbine design works at different dimension and dynamic scales for both wind and hydrokinetic applications.