Overshoot of Wind Forces on a Body Under Step-Function-Like Gusty Winds

The characteristics of unsteady wind forces on a basic shaped body under step-function-like gusty wind were investigated using a specially-equipped wind tunnel. We found that a more remarkable overshoot phenomenon of wind force appeared in case of a gust with a shorter rise time, a lower wind speed and a larger section-size of body. Moreover, it turned out that the overshoot coefficient which was defined by a ratio of its maximum to a steady-state value of wind force was determined by the non-dimensional rise time which was composed by its rise time, gust speed and section-size of a body.