Geometrical scaling effects on experimentally obtained external pressure measurements on an idealized building

Atmospheric wind conditions can affect the performance of mechanical ventilation systems installed in pollutant containment zones to prevent escape of hazardous materials. Wind-tunnel tests to study such effects on mechanical ventilation systems require relatively large geometrical scales, such as 1:40. For any geometric scale, the cross-sectional dimensions of wind tunnels are the limiting parameter to model large-scale turbulent structures of the ABL. Therefore, the representation of large-scale turbulent structures is challenging if the geometric scale becomes too large. To assess the effect of such missing turbulent structures, pressure measurements are performed for two differently scaled buildings and ABLs. The geometrical scaling factors are chosen as 1:40 and 1:300. Results are compared in terms of mean and peak pressure coefficients and the time of exceedance of a threshold pressure. Overall findings suggest that a geometrical scale of 1:40 can be utilized for mechanical ventilation studies, provided that the roof is not installed with ventilation components.