Blade pitch angle and camber optimization of a vertical axis wind turbine using numerical simulation

Abstract

In the pursuit of renewable energy, wind power plays a key role in reducing fossil fuel dependency and mitigating climate change. Vertical Axis Wind Turbines (VAWTs) have gained interest due to their adaptability in various environments. Unlike Horizontal Axis Wind Turbines (HAWTs), VAWTs capture wind from all directions, making them ideal for urban and offshore locations. However, their power efficiency, represented by Power Coefficient (CP), tends to be lower due to complex aerodynamics. Studies emphasize the need for continued pitch angle optimization research to improve VAWT performance [1]. 2D and 3D CFD simulations were applied to analyze aerodynamic flow in VAWTs [2]. The study in [2] served as the benchmark for this research, utilizing ANSYS Fluent to model flow patterns. Although the k-ε model is not ideal for strong pressure gradients, it provides faster convergence [3]. The effect of pitch angle (β) on VAWT efficiency was explored in [1], showing a 6.6% CP increase with a -2° pitch angle at a tip speed ratio (λ) of 4 for NACA 0015 airfoils. Their work highlights the need for further optimization research to make VAWTs competitive with HAWTs. These findings were backed by [4] and [5]. A five-parameter model was developed to explore optimal pitch control and created a Variable Blade Pitch Automatic Optimization Platform (VBPAOP) integrating genetic algorithms with CFD simulations [4]. The effectiveness of individual blade pitching and its impact on performance were experimentally demonstrated in [5]. In this research, 2D Unsteady Reynolds Averaged Navier Stokes (URANS) CFD simulations were performed and validated using the results from [2]. The study's novelty lies in the following: