Parameterized Vertical-Axis Wind Turbine Wake Model Using CFD Vorticity Data

In order to analyze or optimize a wind farm layout, reduced-order wake models are often used to estimate the interactions between turbines. While many such models exist for horizontal-axis wind turbines, for vertical-axis wind turbines (VAWTs) a simple parametric wake model does not exist. Using computational fluid dynamic (CFD) simulations we computed vorticity in a VAWT wake, and parameterized the data based on normalized downstream positions, tip-speed ratio, and solidity to predict a normalized wake velocity deficit. When compared to CFD, which takes about a day to run one simulation, the reduced-order model predicts the velocity deficit at any location within 5-6% accuracy in a matter of milliseconds. The model was also found to agree well with trends observed in experimental data. Future additions will allow the reduced-order model to be used in wind farm layout analysis and optimization by accounting for multiple wake interactions.