Which type of flow is characterized by a Froude number greater than one?

The type of flow that is characterized by a Froude number greater than one is supercritical flow. The Froude number is a dimensionless parameter used to determine the flow regime in open channel hydraulics. Specifically, it is defined as the ratio of the flow velocity to the wave velocity (which is a function of the gravitational force and the channel's depth).

When the Froude number exceeds one, it indicates that the flow velocity is greater than the wave speed, meaning the flow is kinetic energy-dominant and moves rapidly. In supercritical flow conditions, disturbances in the flow, such as waves, cannot propagate upstream, and the flow exhibits features such as a steep surface profile and rapid changes in velocity and depth.

Understanding the concept of supercritical flow is crucial, especially in the context of hydraulic design and analysis in open channels, as it typically results in lower depths and can significantly influence the design of irrigation systems, spillways, and other hydraulic structures.