Wind Farm Wake Simulations in OpenFOAM

In an effort to lower the cost of energy for wind power, wake power losses need to be better predicted. As turbines extract energy from wind, a wake of slower, more turbulent flow is created downstream of the turbine. Because of lower local wind speeds, turbines located in the wake of another turbine do not produce as much power as the upstream turbine. Current modeling efforts fail to accurately predict power losses in downstream turbines by not completely capturing wake effects. Further research to understand and model wake effects is necessary to reduce wake power losses and improve overall wind farm power production. A model is created that simulates a neutrally stratified atmospheric boundary layer (ABL). The neutral ABL simulation is validated against three criteria from experimental data. The model is run using both Large Eddy Simulation (LES) and Reynolds Averaged Navier-Stokes (RANS) solvers to compare the two methods as well as to the commonly used empirical Park model. Wind turbines at various downstream positions are modeled within the neutral ABL simulation using an actuator disc. Results from this model include the power deficit ratio of a turbine located in a wake. Power deficit ratios for LES and RANS simulations are within 2-4% and 15-43% of experimental data, respectively. With the results from these simulations, researchers can improve lower-order models to more accurately represent hundreds of turbines in an entire wind farm and improve efficiency.