Wake meandering under non-neutral atmospheric stability conditions – theory and facts

This paper deals with modelling of wake dynamics under influence of atmospheric stability conditions different from neutral. In particular, it is investigated how the basic split in turbulent scales, on which the Dynamic Wake Meandering model is based, can be utilized to include atmospheric stability effects in this model. This is done partly by analyzing a large number of turbulence spectra obtained from sonic measurements, partly by analyzing dedicated full-scale LiDAR measurements from which wake dynamics can be directly resolved. The theory behind generalizing the Dynamic Wake Meandering model to non-neutral conditions are summarized and linked to the results of the full-scale experimental results. It is concluded that there is a qualitative match between the conjecture behind the Dynamic Wake Meandering model and the dependence of turbulence structure on atmospheric stability conditions, and consequently that there is a potential for generalizing the Dynamic Wake Meandering model to include effects of atmospheric stability.