Abstract
A wind turbine operating inside a wind farm is subjected to increased turbulence intensity and reduced wind speeds resulting in increased fatigue loadings and reduced power production. Furthermore, meandering of the wakes results in increased dynamic loading of the wind turbine. In the present study, a standalone dynamic wake meandering (DWM) model has been developed and implemented in commercial code SIMA. The standalone DIWA model does not require a direct coupling with aeroelastic code, hence it is computationally fast. Although the standalone tool is a good alternative for power and thrust prediction, it does not have the capability to predict the turbine aeroelastic loads. The new DWM program is referred as "Disturbed Inflow Wind Analyzer" (DIWA). Benchmarking studies of DIWA with the literature data are presented and discussed. Overall the DIWA compares well with the literature data and the discrepancies between DIWA and the literature data are discussed. The present studies show that the wake deficit profiles are very sensitive to the eddy viscosity parameters. Finally, the turbulence boxes generated using DIWA have been used for understanding the aeroelastic behaviour of NREL 5MW turbine and one of the wind turbines from the Lillgrund wind park. The estimated power production using both aeroelastic coupled with DIWA turbulence boxes and standalone DIWA (without aeroelastic) are in good agreement with the literature data. The trends of fatigue loads are predicted well, with a few exceptions.