A model of roof-top surface pressure dependence upon local flow parameters

The overall objective of this study is to understand the flow around low-rise buildings. Particular emphasis is placed upon the nature of the separated flow above the front or leading edge of the roof, where the worst suctions on the building are known to occur. Experimental measurements were used, along with predictions from numerical simulations of delta wing vortex flows, to develop a model of the pressure field within the conical vortex separation zone. The model accounts for the change in vortex suction with wind angle, and implies that the increase in suction toward the leading roof corner or apex is the result of increased local wind speed. The model also suggests how different turbulence frequencies influence surface pressure beneath the vortex.