Received: 09 Dec 2015 – Accepted for review: 25 Jan 2016 – Discussion started: 26 Jan 2016
Abstract. This paper provides a quantification of the temporal evolution of physical variables in the atmospheric boundary layer (ABL) relevant for wind energy applications. For this purpose, we use the unique dataset gathered during the BLLAST (Boundary Layer Late Afternoon and Sunset Turbulence) field experiment to validate a large-eddy simulation (LES) model by simulating the complete diurnal cycle of the ABL. In this way, this contribution to the special issue of ACP "The Boundary-Layer Late Afternoon and Sunset Turbulence project" satisfies the purpose of the BLLAST experiment: to provide a dataset for the validation of numerical simulations aiming to study transient BL processes. For wind energy applications, we are investigating the behaviour of different physical parameters which are relevant in the height region where a wind turbine operates. This results in a quantification of the diurnal cycle influence on the vertical wind shear, the stratification and the turbulence intensity in the atmosphere. Further, the impact of different heterogeneous surface conditions on shear near the surface layer of the ABL is investigated.
How to cite. Englberger, A. and Dörnbrack, A.: The impact of the diurnal cycle of the atmospheric boundary layer on physical variables relevant for wind energy applications, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2015-995, 2016.
A numerical simulation of the diurnal cycle is performed with an evaluation focusing on the operating height of a wind turbine (lowest 200 m). The prevailing wind and the atmospheric turbulence depend on the time of the day, with a larger vertical gradient of the wind at night and an increase in atmospheric turbulence during day. Further, the amount of shear correlates with the heterogeneity of the surface. These dependencies affect the wake structure and the loading a wind turbine experiences.
A numerical simulation of the diurnal cycle is performed with an evaluation focusing on the...