The employment of numerical methods to solve engineering problems is a reality, as well as, the worldwide concern about the need of renewable and alternative energy sources. Thus, this work presents a computational model capable of simulating the operating principle of some Wave Energy Converters (WEC). To do so, the device is coupled in a wave tank, where the sea waves are reproduced. The Finite Volume Method (FVM) and the Volume of Fluid (VOF) model are adopted. The results showed that the converter's operating principle can be numerically reproduced, demonstrating the potential of computational modeling to study this subject.