Hybrid free-surface flows in a two-dimensional channel.

Hybrid free-surface flows past disturbances in a two-dimensional channel are identified and studied. The fluid is assumed to be inviscid and incompressible, and the flow to be steady and irrotational. The disturbances consist of a step in the bottom of the channel and a flat object lying on the free-surface (e.g., a sluice gate). A weakly nonlinear one-dimensional analysis is used to classify the possible types of solutions, and nonlinear solutions are obtained numerically by a boundary integral equation method.