Abstract
The characteristic of roll-wave flow, which is a flow with high Froude number which appears on the steep slope, is hardly known at present. In laboratory experiment, it was difficult to measure the flow profile which is a thin sheet flow having the characteristic of a wave and a flow.
In this study we measured the velocity field of the roll-wave flow using PIV technique. We also investigated the behaviors of the velocity field in each region separated into five parts of one wave length. As a result, the relationship between velocity field and the water depth in each part was clarified. It also appeared that the velocity profile is grater than a log-law profile at every region.
