Drag coefficients of bodies in aerated flows have not yet been shown clearly. For design purposes, it is necessary to clarify the drag force acting on various bodies in high-speed aerated flows, such as baffle piers on chutes, or boulders in mountain rivers. Also, it is significant to know the drag force acting on human legs in aerated flows, because of the refuge from floodwaters entering the staircase between the ground and underground spaces in an urban area. In this paper, the general expression for the drag coefficient of various bodies in aerated flows is reasonably established on the basis of flow characteristics of aerated flows. Also, in stepped channels, drag coefficients of various cylindrical bodies and a model leg are obtained from aerated flow characteristics.
