Investigating the Hydrodynamics of Triangular Artificial Reefs: The Impact of Structural Parameters on Flow Field Characteristics and Sediment Scouring

Abstract Marine ecosystem restoration increasingly relies on artificial reefs (ARs) as critical tools for enhancing biodiversity and sustaining fishery resources. While ARs generate ecologically beneficial hydrodynamic features through upwelling and wake regions, the resulting near-seabed flow patterns can induce sediment scouring that compromises structural integrity and ecological functionality. Here, a systematic investigation of triangular ARs is presented. The hydrodynamic and ecological performance of these ARs (characterized by upwelling, wake region, and sediment scouring) is governed by three interdependent structural parameters: base angle (α), height (h), and length (l). Through three-dimensional computational fluid dynamics (CFD) simulations performed using OpenFOAM, combined with analysis of existing experimental scour data, we quantify the relationships between these structural parameters and three critical performance indices: upwelling index (Iu), wake index (Iw), and scour index (Is). Analysis using Generalized Linear Model (GLM) reveals that α exerts dominant control over both the Iu and Is, while h demonstrates limited influence on these indices. By developing a comprehensive performance index and employing Kriging interpolation with Bayesian optimization, we identify an optimal triangular AR configuration (α = 30.3°, h = 9.7 cm, l = 33.4 cm) that maximizes ecological benefits while minimizing scour effects. Our findings establish a quantitative framework for AR design optimization, advancing the development of sustainable marine infrastructure.