Experimental Study on the Effect of Ocean Wave Characteristics on Air Pressure in Oscillating Water Column Device

Abstract

Ocean wave energy conversion process in Oscillating Water Column (OWC) device is affected by several parameters. Wave characteristics are an important parameter that determines the level of water fluctuations in the water column. The later parameter is a main factor which influences air pressure in the air column. One of the important wave characteristics is wave steepness (H/L), which is ratio of wave height to wave length. This experimental study analyzed the effect of wave steepness to wave energy. Furthermore, air pressure in the air column of the OWC device is influenced the effects of changes in wave energy converted by OWC device. Testing was performed with several variations of height and wavelength for three different water depths. Wave height change data was recorded with ultrasonic sensor and stored on the CPU via a data logger. The test showed that the deeper the water, the smaller the wavelength and the greater the wave height. In addition, wavelength increase with the increasing of wave period, vice versa wave height decrease with the increasing of wave period. This condition produced different wave steepness so that the wave energy also changes. Data analysis showed the wave steepness of the test results with the biggest pressure change that corresponds to the actual wave steepness generated by the wind at ocean achieved at water depths h = 240 mm with wave height H = 82.8 mm and L = 1250 mm.