A low-order simulation model for wind turbine infrasound prediction

Wind energy is one of the fastest-growing renewable energy technologies. One of the environmental concerns associated with wind energy development is noise emission from wind energy facilities, especially the low-frequency noise and infrasound that allegedly raises public health concerns. In order to analyze the noise emission from wind turbines and to aid future wind energy development, a numerical simulation tool for the prediction of low-frequency noise and infrasound emission from wind turbines is developed. The simulation tool is a low-order model developed by combining aerodynamic noise theories and basic working principles of wind turbines. 2-D airfoil aerodynamics calculation is coupled with a subroutine that solves Ffowcs Williams-Hawkings (FW-H) equation in time domain. By omitting unsteady aeroacoustics mechanisms, the low-order simulation model is capable of computing infrasound emissions from multiple wind turbines simultaneously. By utilizing the low-order simulation model, the effects of wind directions, wind turbine locations, and phases of wind turbine rotations on the consequent aerodynamic infrasound are studied. Results of aerodynamic infrasound computation imply that wind farm configuration or wind turbine phase adjustment can help reduce the noise level at certain locations, which makes the low-order simulation model a useful tool to aid wind farm siting and controlling.