Wind Tunnel Experiments of the Mean Wind Profile Characteristics over a Large Central City

Abstract:

In the paper, the real buildings within a range of 1.8km×8.0km in a central area of Shanghai along the direction of WNW near Tongji University were reconstructed by scale models. The influence of the urban terrain features, the differences between far and near terrains and the distance between the starting position of the terrain and the observation location on mean wind profiles and wind field characteristics were discussed with wind tunnel experiments. Results showed that the gradient wind height is on the increase, until the wind profile becomes steady, with the increase of the distance between the starting position of the terrain and the observation location; the wind profile is influenced by terrain features greatly; the ground roughness exponents of the urban district in Shanghai are estimated as 0.50 to 0.75, which is far greater than the corresponding value 0.30 in the load code for the design of building structures in China. The value of ground roughness exponent of the urban district of large cities presented by the load code for the design of building structures should be increased.