A comparative study of RANS-based turbulence models for an upscale wind turbine blade

Abstract

Computational fluid dynamic (CFD) numerical simulations are providing alternative to experimental methods in preliminary analysis of aerodynamic behavior for large wind turbines. Shortcomings inherent by experimental methods have popularized the three dimensional CFD methods. This paper, therefore, presents a numerical analysis for NREL 5MW wind turbine rotor using a single moving reference frame approach. ANSYS Fluent is employed to model airflow over the blade’s surfaces using Reynolds average Navier–Stokes equations. A steady-state incompressible pressure based solver is applied in form of absolute velocity formulation. Four turbulence models are used: $$k-\omega$$ SST, $$k-\epsilon$$ RNG, $$k-\epsilon$$ realizable and Spalart Allmaras to determine the aerodynamic torque. Mesh independence study and validation is also performed. In addition, the predicted flap-wise bending load and comparison of pressure distribution for the four turbulence models are evaluated at different sections of the blade. Due to absence of experimental data for employed blade model, the obtained aerodynamic torque was compared with other reliable numerical simulation results.