Abstract
In this work, different turbulence models were applied to predict the performance of a DU-06-W-200 airfoil, a typical choice for vertical-axis wind turbines (VAWT). A compromise between simulation time and results was sought, focusing on the prediction of aerodynamic forces and the developed flow field. Reynolds-averaged Navier–Stokes equation (U-RANS) models and Scale-Resolving Simulations (SRS), such as Scale-Adaptive Simulation (SAS) and Detached Eddy Simulation (DES), were tested, with k − ω -based turbulence models providing the most accurate predictions of aerodynamic forces. A deeper study of three representative angles of attack (5 ° , 15 ° , and 25 ° ) showed that U-RANS models accurately predict aerodynamic forces with low computational costs. SRS modeling generates more realistic flow patterns: roll-up vortices, vortex packets, and stall cells have been identified, providing a richer unsteady flow-field description. The power spectrum density of velocity at 15 ° has confirmed a broadband spectrum in DES simulations, with a small peak at a Strouhal number of 0.486. Finally, indications regarding the selection of the turbulence model depending on the desired outcome (aerodynamic forces, airfoil flow field, or VAWT simulation) are provided, tending toward U-RANS models for the prediction of aerodynamic forces, and SRS models for flow-field study.
Highlights
In a world context in which living without electricity is almost inconceivable, the development of renewable and sustainable energy sources is of vital importance
The formulations based on the SST model are not so accurate in the U-RANS and Scale-Adaptive Simulation (SAS) cases, especially at higher angles of attack
The models that seem more suitable for the prediction of airfoil aerodynamic forces are the U-RANS k-ω Standard, the SAS and the Detached Eddy Simulation (DES), being the U-RANS k-ω Standard model the best recommendation if the only objective of the study is the prediction of the aerodynamic forces for an airfoil
Summary
In a world context in which living without electricity is almost inconceivable, the development of renewable and sustainable energy sources is of vital importance. Research has traditionally focused on horizontal-axis wind turbines (HAWTs), vertical-axis wind turbines (VAWTs) have important advantages, the main one being that they are capable of working independently of the wind direction. They can produce energy from lower wind speeds, so they can be placed nearer to the ground, making installation and maintenance easier. Due to the continuous changing of the relative position of the blades with respect to the incoming wind, flow behavior is much more complex, with the blades working even at stall conditions during part of the rotation cycle Considering this particular characteristic, the importance of employing an optimized airfoil design for turbine blades is evident
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
