Interaction between hydraulic jump and turbulent boundary layer-Three dimensional undular jump

The type of hydraulic jump changes according to the Froude number F. When F is less than about 1.2, the water surface is smooth. On the otherhand, for a larger F, a series of small rollers develops on the surface of the jump. However, when the influence of side walls is strong enough to affect the flow at the central part of the channel, the jump is smooth and the height of the jump increases appreciably, even if F is fairly larger than 1. 2. In this paper, we showed that this phenomenon is caused by an interaction between the jump and the turbulent boundary layer.