Author(s): Takayuki Tanaka; Yasuko Yamamoto
Linked Author(s): Takayuki Tanaka
Keywords: Hybrid groyne; Numerical analysis; Suspended solids; IRIC
Abstract: The Aizuma River, which flows through Aichi Prefecture, has three right-angled groyne on its right bank approximately 300 m downstream from the confluence to prevent riverbank erosion during floods. This hybrid groyne combines the impermeable characteristics of a masonry structure and the permeable characteristics of a piled-out groyne. The objective of this study is to obtain new knowledge on river flow with hybrid groyne by numerical analysis of the flow field and suspended sediment behavior around the groyne. This study is analyzed using the NaysCUBE solver of iRIC software. The analysis pattern is to compare the differences in river flow and suspended sediment behavior when no groyne, impermeable groyne only, and hybrid groyne are installed for three different boundary conditions. The analysis results show that in the case of impermeable groyne, the transverse flow velocity was large at the tip of the groyne located at the most upstream end. In addition, the impermeable groyne had a pronounced control effect of concentrating the flow direction in the center of the main flow section, resulting in the generation of large circulating flows inside the groyne. In the analysis of suspended solids behavior were captured more effectively by the impermeable groyne than by the hybrid groyne.
Year: 2024