Experimental Evaluation of the Effect of Incident Wave Frequency on the Performance of a Dual-chamber Oscillating Water Columns Considering Resonance Phenomenon Occurrence

Abstract

This paper has experimentally investigated the performance of a dual-chamber oscillating water columns (OWC) imposed on Caspian Sea wave’s characteristics. Experimental runs were performed for three water draft depths of 10, 15, and 20 cm and eight wave frequencies ranging from 0.4 to 0.7 Hz. Also, if the converter consists of only one chamber, the power generated was 75W; however, by placing the second chamber serial behind the first chamber, the converter power increased to 116 watts (55% improvements). The results showed that if the frequency of the incident wave is not in the natural frequency range, the converter performs is better at the lowest water draft depth (10 cm). Whereas if the frequency of the incident wave is in the natural frequency range, the converter will have the best performance at the maximum water draft depth (20 cm). As the power generated at a water draft depth of 10 cm increased by 3.8% compared to a water draft depth of 20 cm. But within the natural frequency range and by resonance, the power produced at a depth of 20 cm is 27.3% more than the power generated at a depth of 10 cm.