Abstract
The present study focused on the characteristics of dispersing peak wind pressure coefficients acting on a square cylinder with an aspect ratio of three, which were obtained in wind tunnel tests. The experiments were carried out at a wind direction angle of 0 degrees, and 18369 waves of time history of wind pressure coefficients, which are equivalent to ten minutes of real time, were obtained. The peak wind pressure coefficients show a wide dispersion range near the leading and trailing edges on the side surface. Furthermore, it was confirmed that the range is larger in the lower part of the square cylinder. The convergence curve to the expected value with respect to the number of ensemble averages indicates that the rate of convergence follows a logarithmic function when the number of averages exceeds 5～30. Fluctuations of wind pressure coefficients when absolute value of the peak wind pressure coefficient is high were discussed using power spectral density functions. A significant difference was confirmed in the lower part of the square cylinder in case that the dispersion range is large. Additionally, a large difference was observed at non-dimensional frequencies of 10-3 for the front surface and 10-1 for the leading edge on the side surface in the lower part, and this suggests that the dispersion of the peak wind pressure is caused by the flow fluctuations at these frequencies.
