Abstract
The mean velocity and turbulence intensity distributions were experimentally investigated for both water phase and air phase of air-water stratified two-phase flows. Mixing-length model in wind waves was expanded in the air flow of two-phase flows. It was clarified that the shear distribution was parabolic when there exist both the bed shear stress and the interface shear stress. In water layer, non-linearity increases as the ratio of friction velocities in both layers increases. In this way, it was found that the relative velocity between the air flow and the water flow is closely related to the turbulence structure near the free surface in two-phase flows.
