Stochastic turbulence generation by flow alteration in computational fluid dynamics simulations
Atmospheric turbulence characterization is of remarkable interest since it is the direct input to Wind Energy Converters (WEC's). The design of such systems is significantly influenced by the inflow conditions they are going to experience during their operating lifetime. In the sense of looking for a proper representation of inflow atmospheric turbulence the paper presents the results from several computational fluid dynamic (CFD) simulations in which inflow turbulence is generated by adding force terms to the governing equations in a tunnel-shaped domain. The contributions are obtained by resolving an Ornstein-Uhlenbeck equation, which is also used to generate synthetic time series independently from the computational simulations. Forcing is applied in two configurations: affecting a complete cross section or in a multiscale grid. Results from both cases are compared to atmospheric measurements and the main characteristics of the simulated turbulent fields are discusse d. Turbulence is handled using LES with one equation eddy viscosity model for the subgrid scales in OpenFOAM.