Wind Tunnel Experiments on Flight Characteristics of Windborne Debris upon Low-Rise Building

Abstract

In strong wind events such as hurricanes and tornadoes, windborne debris is the main cause of disasters and buildings destruction. Roof slabs, tiles, and other enclosure components may become potential windborne debris. In the present research, a series of wind tunnel experiments were carried out to investigate the flight characteristics (i.e., the trajectory distribution and the flight speed) of debris released at different positions on the windward roof of a low-rise building. The results show that the initial position of debris has an important influence on the trajectory distributions and flight speed. Along the Y-axis, the trajectory distribution of debris released near the central axis of the roof is wider than those of debris whose initial positions lying closer to the side. As for debris which is closer to the central axis of the roof, a wider trajectory distribution in the vertical direction and higher flight speed are observed when the debris is released closer to the windward eave. And for debris whose initial positions have the same distance from the windward eave, the closer the initial positions to the central axis, the lower the total speed is. The total speed of the debris is mainly composed of the vertical (Z-axis) speed component at the beginning of the flight, and gradually, the proportion of horizontal (X-axis) speed keeps increasing with time passing by.