Aerodynamic Performance Prediction of Straight-Bladed Vertical Axis Wind Turbine Based on CFD

Abstract

Numerical simulation had become an attractive method to carry out researches on structure design and aerodynamic performance prediction of straight-bladed vertical axis wind turbine, while the prediction accuracy was the major concern of CFD. Based on the present two-dimensional CFD model, a series of systematic investigations were conducted to analyze the effects of computational domain, grid number, near-wall grid, and time step on prediction accuracy. And then efforts were devoted into prediction and analysis of the overall flow field, dynamic performance of blades, and its aerodynamic forces. The calculated results agree well with experimental data, and it demonstrates that RNG k-turbulent model is great to predict the tendency of aerodynamic forces but with a high estimate value of turbulence viscosity coefficient. Furthermore, the calculated tangential force is more dependent on near-wall grid and prediction accuracy is poor within the region with serious dynamic stall. In addition, blades experience mild and deep stalls at low tip speed ratio, and thus the leading edge separation vortex and its movement on the airfoil surface have a significant impact on the aerodynamic performance.

A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

“…These models can be broadly classified into four categories: momentum models, vortex models, cascade models and computational fluid dynamic (CFD) models. Based on [17,[23][24][25][26][27][28][29][30], a quick literature survey was performed on most used models. Table 1 presents the relevant features as well as the advantages and shortcoming for each model category.…”

3D CFD Analysis of a Vertical Axis Wind Turbine

“…Furthermore, studies of dynamic stall show that the Shear Stress Transport (SST) κ − ω turbulence model performs better than the κ − ω model, as reported by Ekaterinaris and Platzer [24] and Qian et al [25]. Only recently have some researchers carried out three-dimensional CFD simulations [26,27]. Howell et al [26] provided a three-dimensional CFD model based on the Re-Normalisation Group (RNG) κ − turbulence model, and the effects of turbine solidity, roughness and tip vortices were considered.…”

“…Howell et al [26] provided a three-dimensional CFD model based on the Re-Normalisation Group (RNG) κ − turbulence model, and the effects of turbine solidity, roughness and tip vortices were considered. Zhang et al [27], analyze a three-bladed straight wind turbine, using a NACA 0015 airfoil with a chord length of 0.4 m and a blade length of 2 m with 4 m in diameter. The aim of the present paper is to numerically compare different Darrieus turbine configurations that differ for the twist angle of the blades.…”

3D URANS analysis of a vertical axis wind turbine in skewed flows

“…The external dimensions are 14D x 30D x 12D and the wall distance is 1*10-4c, necessary for an averaged y+ < 5, following a mesh sensitivity analysis performed in order to verify if the grids adopted were sufficiently fine to resolve the primary flow features. Figure 1 shows the analysis for the 2D model for the 17m Darrieus VAWT and the 3D model for the small H-Darrieus VAWT; the 3D model of the SANDIA turbine has been excluded from this analysis due to the high number of cells of the domain, but the mesh adopted is similar to that used by Howell [16] and Zhang [17].…”