Numerical Predictions of the Generated Work in an Air-Compression Chamber Driven by an Oscillating Water Column

Abstract

In the present work, we have studied the performance of an open compression chamber with compressed air and driven by an oscillating water column. Recognizing the existence of a free-surface for the water column, the interface position between the trapped-air and water volume -together with the motion of the column-, is described by a non-linear energy equation that reflects the main dynamic characteristics. The above governing equation is posed in dimensionless form and solved by conventional numerical methods. In addition, a theoretical approximation of the first order in to predict the resonant frequency of the oscillatory system is derived to complete the analysis. The numerical results of the above governing equation serve us to estimate the dimensionless work done by the oscillating water column as a function of three dimensionless parameters: a characteristic Froude number, , and two equivalent quasi-geometric parameters, and , defined below. The predictions show that the influence of the geometry and the involved physical parameters exert a great influence on work generation into the air-chamber.

Comparison of the performance of oscillating water column devices based on arrangements of water columns

“…Among studies of OWC devices, studies of how to improve the performance of OWC devices are one of the most conducted studies for device commercialization. In this case, some studies concentrated on using various control devices, such as wave characteristics, shape parameters of the device, and exhaust duct system, on increasing the efficiency of OWC [4,5].…”