Towards forecasting of wind comfort

Numerical results of a K-¿ model are compared with LDA measurements. Hot wire results are shown to be unsuitable if turbulence intensity (TI) is over 45%. Numerical results for isolated buildings are within 10-20% of experiments, provided that the K-¿ model constant Cµ is matched to the approach flow value. For skimming flow over an obstacle group, the standard Cµ is appropriate. A parametrization of turbulence intensity as a function of local wind amplification factor has been obtained for flow over isolated obstacles. This parametrization can only be verified with numerical simulation or with LDA; not with hot wire anemometry. The turbulence intensity parametrization can be used to predict discomfort or danger probability as a function of wind amplification factor. The affected area can be determined with a parametrization of the influence radius of a building as a function of building width and height.