인공어초 후류역을 증가시키는 두 가지 관점

Abstract

Wake region of an artificial reefs (AR) is a significant space to recruit marine species around the AR because the region gathers nutrients and prey (e.g., phytoplankton). Previous studies have focused on relatively small, simple ARs for the estimation of wake regions. Thanks to progressive artificial reef industry, nowadays relatively large, complex ARs are being installed on the seabed; hence, it is necessary to investigate how to secure wake region of those ARs. In this study, the concept of wake volume was used to estimate the wake regions of five relatively complex artificial reefs (ARs). The element-based finite volume method was used to estimate wake volume, and its fluctuation due to the size of the ARs and the inflow velocity was calculated. From the analysis results, it was found that the thickness and area of the structural members of the ARs are important to secure wake region. However, wake region was not created if the AR is composed of only a thin steel frame. This indicates that the function of the structural members of the ARs that blocks the flow is important for the creation of the wake region. In the case of AR in which a wake region occurs, the AR size (height) has a significant positive correlation with the magnitude of the wake region, and if the inflow flow velocity is 1.0 m·sSUP-1/SUP or more, a sufficient eddy currents occur and accordingly no variation in wake volume is observed. Thus, to increase wake region, it is shown that not only the size of AR, but also the thickness and area of the structural members play an important role.