Engineering approach for a CFD inflow condition using the precursor database method

The Precursor Database Method can be utilised to produce turbulent inlet boundary conditions for a LES to determine the wind loads on a high-rise building. The Precursor Database Method is an embedded method within Computational Wind Engineering but is, however, often a minor subtask in a study and the quality assurance is usually not comprehensive. 4 precursor models are assessed and validated with an Experimental Wind Tunnel. By rearranging the roughness elements in the Digital Wind Tunnel, the grid size was significantly reduced, while preserving the turbulent flow. Furthermore, the wind tunnel inlet contraction was added to the CFD model and reduced a speed-up error near the sidewalls. The paper suggests guidelines for a standard CFD setup of a Precursor Database model that is viable for industrial employment. It clarifies the considerations of geometry, temporal and spatial discretisation and the utilisation. Finally, the guidelines elaborate on how to secure the transfer of the mapped flow from the precursor domain to the test section domain.