SIMULATION OF WIND TURBINE FLOW USING THE ACTUATOR LINE METHOD IN NEK5000

Wind turbine wake models are used to estimate the velocity profile and magnitude downstream of wind towers in large wind farms. Current models are based on simple geometric and empirical factors, which typically overestimate individual turbine output. Recent research has focused on using improved models of turbine rotors, combined with computational fluid dynamics (CFD) programs to simulate turbine wake flow. In this paper, we report on our efforts to simulate flow past wind turbines using a new adaptation of the actuator line method for turbine blade modeling. This method creates a geometric representation of each rotating turbine blade. Grid points in the CFD flow field are selected within the outline of the blades and near downstream planes, and the aerodynamic forces are calculated using traditional blade element equations. Blade forces are then input as body forces into the Navier Stokes equations in the host CFD program. This model is combined with the advanced parallel CFD code, NEK5000, which has been proven to provide high-resolution results with significantly reduced compute resources. Program subroutines are developed to generate the actuator line and blade geometry, and to calculate the blade lift and drag forces. Details of the actuator line setup and calculations, CFD flow simulation setup, and results from current development runs simulating a single turbine will be presented. Current results are consistent with published research. Lessons learned, and a roadmap to ongoing development are also discussed.