Behrad Alizadeh Kharkeshi^{1}, Rouzbeh Shafaghat ^{*}^{1}, Rezvan Alamian^{1}, Amir Hossein Aghajani Afghan^{1}

In this paper, the effect of the draft depth (as a dimensionless number) and characteristics of the incident wave on free surface oscillation, velocity, and the output power of an OWC has been analytically and experimentally investigated. Therefore, the governing equations of hydrodynamic performance inside the oscillating water column chamber were first presented by assuming a mathematical model based on the potential flow theory. Then, a 1:10 single chamber OWC has been experimentally investigated in a wave tank, by considering the Caspian Sea wave characteristics. Comparing the obtained results showed that there is a good agreement between the theoretical solution and experimental test data. According to the results, increasing the frequency of the incident wave increases the free surface oscillation outside the chamber, while the results inside the OWC are different. In other words, under these conditions, free-surface oscillations inside the OWC and subsequently, the velocity and flow rate of the orifice decrease. So, the power generated will decrease too. Also, the effects of draft depth have been theoretically and experimentally analyzed for three depths and turned out that increasing the depth of drafts from 5 to 25 cm and frequency from 32 to 42 rpm causes a decrease in power generation.

Type of Study: Research Paper |
Subject:
Offshore Hydrodynamic

Received: 2020/06/28 | Accepted: 2020/09/12

Received: 2020/06/28 | Accepted: 2020/09/12

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