Comparison of RANS, LES and wind tunnel experiments for the calculation of wind loads on a low-rise building.

Wind-resistant design of buildings and their components plays an important role to reduce losses due to extreme wind events. Computational Fluid Dynamics (CFD) provides a powerful tool to calculate wind loads on buildings, but validation is required to assess their performance. Reynolds-averaged Navier-Stokes (RANS) simulations support fast calculations, but have lower fidelity and require empirical relationships to calculate turbulent statistics, such as the root-mean-square pressure coefficients (C_p). In contrast, Large-eddy simulations (LES) are computationally more expensive, but have higher fidelity and all statistics can be calculated directly. The objective of this study is to compare mean and fluctuating C_p values between wind tunnel experiments, RANS and LES of a low-rise office building. The analysis considers 1) the isolated building, and 2) the building in its urban environment, to evaluate interference effects for different wind directions. Preliminary results for the dominant wind direction show good agreement for the mean C_p. Future work will extend the comparison to turbulent statistics.