Flow and Erosive Stresses at the Base of a Headcut

This paper revises current understanding of the flow at the base of a headcut and suggests a new model which employs the concept of a vortex flow. A distinctive feature of the vortex flow is the presence of the upstream-directed jet, which attacks the vertical headcut boundary. Numerical simulations are performed to demonstrate the significance of the effects of the upstream-directed jet for breach development.