Computational analysis of horizontal-axis wind turbine by different RANS turbulence models

Abstract

Numerous numerical investigations of isolated horizontal-axis wind turbine rotor consisting of three blades have been performed in ANSYS FLUENT 16.2. These flows are three-dimensional, complex, unsteady, turbulent and vortical with several interesting flow phenomena, such as flow separation and dynamic stalling, appearing. Flow field is modeled by Reynolds Averaged Navier-Stokes (RANS) equations. Two different turbulent models are tried: Spalart- Allmaras and k-ω SST. For resolving the rotational motion of the blades both Moving frame of reference (MFR) and Sliding mesh (SM) approaches were employed. Both computational approaches are briefly explained. Obtained numerical results are compared to available experimental data. Presented results include fluid flow visualizations in the form of pressure and velocity contours, sectional pressure distributions and values of power and thrust force coefficients for a range of operational regimes. Although obtained numerical results vary in accuracy, all presented numerical settings seem to slightly underestimate the global wind turbine parameters (power and thrust force coefficients). Turbulence can greatly affect the wind turbine aerodynamics and should be modeled with care.