Extended THETA for Site Assessment

Funding: BMWi
Partners: Wobben Research and Development GmbH (WRD), German Aerospace Center – DLR, Institute of Aerodynamics and Flow Technology, ForWind – Carl von Ossietzky University Oldenburg
Duration: 01/2016 – 09/2019


Unlike purely aerodynamic CFD codes, weather influences play a major role in atmospheric flow. These include both solar radiation and the modification of local wind conditions through large-scale weather systems. The aim of the project is to transfer high-resolution numerical methods for site simulation taking account of thermal stratification of the atmosphere to the industrial process of site assessment. For this, the CFD solver THETA, which is established within industrial flow simulation, is being expanded in two stages to provide a simulation of atmospheric boundary layer turbulence, first for thermally neutral stratification, then for non-neutral stratification. For this, the THETA code needs to be adapted considerably.

For the code to be usable for site assessment, atmospheric simulation methods must be incorporated for different atmospheric situations and the typical events that arise on the ground. Conditions to be incorporated include follow-ups of other wind turbines, afforestation, various kinds roughness in the terrain and the ambient weather conditions. Another of the aims of the sub-project is the full verification and validation of the code based on measurements and other simulation results for numerous exemplary cases.