Modeling the mean wind loads on cylindrical roofs with consideration of the Reynolds number effect in uniform flow with low turbulence

• The wind tunnel tests of cylindrical roofs revealed an earlier shift in the transitional Reynolds number as the aspect ratio decreases.
• A modified pressure model was proposed to represent the experimental data for the cylindrical roofs.
• The Reynolds number effect was taken into account by appropriate estimation of the fitting parameters as functions of Re.
• The proposed model was found to provide reliable wind load estimates for both cylindrical and spherical roofs.

The influence of Reynolds number on the mean wind loads acting on cylindrical roofs with different aspect ratios (rise to span ratio, R/D) has been investigated experimentally. The spans D of the cylindrical roof models were 0.2 and 0.6 m, and the Reynolds numbers, based on D, ranged from 6.90×104 to 8.28×105. Three aspect ratios were studied; R/D=1/2, 1/3 and 1/6. The surface pressure distributions and force coefficients were determined using wind tunnel measurements in uniform flow with low turbulence. The effects of the different aspect ratios and Reynolds numbers were briefly discussed. The aim of this investigation was to find a simplified approach to parameterize estimation of the pressure coefficients Cp, which considers the influences of the aspect ratio of the roof model together with the Reynolds number. It was found that a modified pressure model, in terms of a re-normalized formation, represented the experimental data accurately for the cylindrical roof model with a variety of aspect ratios. This approach was also found to be reliable for evaluating wind pressure distributions on cylindrical and spherical roofs.