  In this work we present the mathematical model and simulations of a
particular wave energy converter, the so-called oscillating water column. In
this device, waves governed by the one-dimensional nonlinear shallow water
equations arrive from offshore, encounter a step in the bottom and then arrive
into a chamber to change the volume of the air to activate the turbine. The
system is reformulated as two transmission problems: one is related to the wave
motion over the stepped topography and the other one is related to the
wave-structure interaction at the entrance of the chamber. We finally use the
characteristic equations of Riemann invariants to obtain the discretized
transmission conditions and we implement the Lax-Friedrichs scheme to get
numerical solutions.
