This work presents a 2D numerical study of an Oscillating Water Column (OWC) converter considering physical constraints in its outlet chimney to represent the turbine pressure drop. Two strategies were adopted. The first considers different dimensions for a physical constraint similar to an orifice plate, being the analysis performed in a laboratory scale. After that, other physical restriction with geometry similar to a rotor turbine was investigated in a real scale by means a dimensional variation. The numerical results indicate the importance of consider the pressure drop caused by turbine in the analysis of the OWC behavior.