An investigation of Reynolds number effects on the steady and unsteady aerodynamic forces on a 1 : 10 scale bridge deck section model

In general, the aerodynamic stability of long span bridges is evaluated based on the results of wind tunnel tests in the low Reynolds number region, because in almost all wind tunnel tests, it is impracticable to satisfy Reynolds number similitude. Therefore, from a wind engineering point of view, in order to correctly evaluate conventional wind tunnel test results, Reynolds number effects on the steady and unsteady aerodynamic force coefficients acting on bridge decks must be carefully investigated. This paper gives the results of research on Reynolds number effects on steady and unsteady aerodynamic force coefficients measured in the wide Reynolds number region from 1.1×104 to 1.5×106 based on the dimension of deck height. Three types of bridge deck section models with different scales, including a 1 : 10 scale model, were used in three types of wind tunnels, including the NRCC 9 m×9 m wind tunnel. It was found that conventional wind tunnel test results in the low Reynolds number region are conservative for wind resistant-design of bridge decks.