CFD Analysis of a Vertical Axis Wind Turbine for Urban Energy Production - A Comparative Study of High and Low Fidelity Models

12/09/2024

Wind energy is a crucial component of the global energy transition, with vertical axis wind turbines (VAWTs) gaining renewed interest in the last decade due to their advantages in urban environments. However, a knowledge gap exists between the horizontal and vertical axis configurations, particularly in numerical simulation tools, especially regarding high-fidelity 3D Computational Fluid Dynamics simulations. This study aims to expand the understanding of both low-fidelity and high-fidelity models applied to VAWTs through a comparative analysis conducted on a 5-blade helicoidal VAWT design to evaluate the advantages and limitations of various models across the fidelity spectrum. The models examined include the low-fidelity Lifting Line Free Vortex Wake (LLFVW) model, a hybrid model combining 2D Unsteady Reynolds-Averaged Navier-Stokes (URANS) data with the LLFVW model, and two high-fidelity URANS models utilizing the industry-standard k−ω Shear Stress Transport (SST) model and the γ −Re_θ transition model. The results revealed a significant discrepancy between low-fidelity and high-fidelity models, with LLFVW significantly overestimating power output. Further analysis suggests that this discrepancy is attributed to the low-fidelity models’ inability to accurately capture blade-wake interactions, particularly in the downwind region, and forces in regions with dynamic stall phenomena. The hybrid model showed promising results, demonstrating closer alignment with URANS values and improved correlation in the downwind region. No substantial differences were observed between the standard k − ω SST model and the transition model.

Authors in the community:

• 

  P

  Pedro Afonso Simões Gonçalves

  ist1105745

Supervisors of this institution:

• 

  F

  Fernando José Parracho Lau

  ist13198

• 

  G

  Guilherme Nuno Vasconcelos Beleza Vaz

  ist14108

mechanical-engineering - Mechanical engineering

eng - English

Instituto Superior Técnico