Numerical study of internal waves, turbulent mixing, and behavior of particulate matter around artificial mound reef

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K18431
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology; Aquatic bioproduction science
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: FURUICHI Naoki 国立研究開発法人水産研究・教育機構, 水研機構(神栖), 主任研究員 (70588243)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: マウンド礁 / 内部波 / 乱流 / 粒子 / LES

Outline of Final Research Achievements

A large-eddy simulation (LES) study on tidally-induced internal waves and turbulent mixing processes over a marine bank (or an artificial mound reef) was conducted and the obtained results were used to examine the behavior of suspended particulate matters. After verifying the simulated results with the results from hydraulic model experiment, we carried out several numerical experiments to examine the effects of the existence of marine bank and sea water density stratification on the behavior of the suspended particulate matters. The simulated results demonstrated that the marine bank played important roles in the upward transport of particles from the near-bottom to the upper areas, especially under the stratified density conditions.

Free Research Field

水産工学・海洋物理学・海岸工学

Academic Significance and Societal Importance of the Research Achievements

国・都道府県の事業によって人工マウンド礁（以下、マウンド礁）の設置が進められてきた。マウンド礁の設置によって、海洋内の物質輸送機構が変化し、一次生産量ひいては水産資源の増大が期待される。本研究は、高解像度の乱流計算手法であるLESと粒子追跡実験とを組み合わせることで構造物（小規模地形）近傍の局所的な流体・物質輸送に関する信頼性を高めた考察を行った。このようにして得られたこの知見は、広域的な海の環境変化を評価・予測するためのモデルの改良や、堆周辺での漁場評価に役立つものと期待される。