This paper represents the effects of geometry and design of an oscillating water column energy converter air chamber on the airflow response. The primary goal of this research is to use different shapes of air chambers, such as rectangular, cylindrical, and conical air chambers with varying cross sections, to optimize the air velocity entering the turbine, to obtain the maximum power available in a progressive wave with a constant period and wavelength. Modeling and numericalsimulation are performed by using the commercial software ANSYS. Since this paper is concerned with the effect of air flow velocity, a vent is located at the chamber's outlet rather than a turbine. In order to obtain the exit air velocity results, the wave system air characteristics results are applied as an input air flowfor three air chamber cases. The results show that the air velocity flow increasedsignificantly from 7.14 m/s in the rectangular air chamber to 10.4 m/s in cylindrical air chamber and reached a maximum of 14.2 m/s in the conical airchamber.