Multiscale Simulation of a Frontal Passage Through a Wind Turbine Array Using the Weather Research and Forecasting Model

Multiscale simulations of a frontal passage interacting with an operating wind farm are conducted using the Weather Research and Forecasting (WRF) model. Mesoscale simulations are downscaled to large-eddy simulations using a series of telescopically nested domains, with an array of turbines on the innermost nest represented using generalized actuator disk (GAD) models. Simulations are compared to data from meteorological towers and dual-Doppler-synthesized wind fields from Texas Tech University Ka-band radars. Both the mesoscale-to-microscale downscaling approaches, and the ability of the GAD models to represent wake characteristics, are examined. The simulations depict realistic wakes that qualitatively match observed characteristics. Use of different meteorological forcing datasets, however, provides very different representations of the wind speed and direction surrounding the frontal passage. A recently developed stochastic perturbation method to accelerate turbulence generation at nested LES inflow boundaries is also examined. Successes, failures, and recommendations for future work are discussed.