FUNDAMENTAL EXPERIMENTAL STUDY ON PROMOTION OF GAS TRANSFER INDUCED BY SUBMERGED BREAKWATER

Abstract

 Wave breaking by submerged breakwaters in coastal areas enhance the transport of oxygen and carbon dioxide gases into the ocean. However, the mechanisms of sub-surface gas transport are still unclear. In this study, we quantitatively investigated waves, turbulence, and dissolved gas transport in a wave-making flume. In particular, we clarified the spatial-temporal variation of the reaeration coefficient using multiple optical DO meters and the structure of wave breaking turbulence using PIV visualization measurements. Based on their information, the hydraulic quantities that seem to dominate the phenomena, such as wave period, waveform, and turbulence statistics, are summarized, and the mechanism of gas transport enhancement by submerged wave breaking is discussed.