Transient wind loading on a single and group of high-rise buildings

Thunderstorm downbursts are transient, small-scale events which are, however, the cause of design wind speeds in many parts of the world. The difficulties in predicting when and where such events will occur make capturing full-scale wind loading data for buildings particularly difficult, and so attention has turned to physically simulating downburst flow fields in the laboratory. The University of Birmingham Transient Wind Simulator (UoB-TWS), a 1 m diameter, pulsed impinging jet facility, has been used to physically simulate a downburst and measure the wind-loading on building models which occurs. For the first time, pressure data have been recorded over both single and multiple building model arrangements, allowing interference effects to be quantified. It is demonstrated that the presence of another building nearby can increase drag coefficients by almost 40%, depending on the separation of the building models and the angle of the wind relative to the models.