Abstract:

In view of the important significance of studying the characteristics of the flow field of wind farms to improve the working efficiency of a wind turbine, using computational fluid dynamics (CFD) method, based on the simulation verification of a single wind turbine, a numerical simulation study was carried out on the flow field characteristics under a wind farm with a single wind turbine and three layout conditions.The distribution characteristics of wind farm speed, impeller pressure, and turbulence vortex under different layout conditions were investigated.Results showed that the wake flow effect behind the impeller is significantly obvious, and the velocity loss decreases with the relative distance increases.The wake velocity ratio at the center of the wind turbine is reduced to a minimum of 0.4.When the relative distance exceeds 4 d, the wind speed can be restored to more than 90% of the initial speed.The velocity ratio of the wake flow presents a negative correlation with the eddy viscosity.When the three wind turbines are arranged in parallel, the wake velocity ratio of each wind turbine is the same.When the three wind turbines are arranged in a staggered arrangement, the wake effect has less influence on the performance of downstream wind turbines.The larger the staggered angle, the smaller the wake loss.

Key words: Flow field characteristics, Computational fluid dynamics (CFD), Wake flow effect, Wind turbine layout