6. CFD simulations

The CFD calculations of wind and rain are described in this chapter. A literature survey on CFD simulations was already reported in section 1.3. In this chapter we first describe the applied models for the CFD calculations of wind and raindrop trajectories (sections 6.1 and 6.2 respectively). The Main Building and its direct surroundings are implemented in the model. Subsequently, wind simulations are carried out for several reference wind speeds and wind directions. Finally, driving rain intensities on the west façade of the Main Building are calculated from the wind simulation results and the raindrop spectra obtained from literature and our measurements. The results are presented in sections 6.3 (wind) and 6.4 (driving rain). The results of the calculations are compared to the full-scale measurements.

The main goal of the chapter is an investigation of the suitability of CFD for driving rain calculations, and especially of the aspects which should be dealt with to obtain reliable results.