Hydrodynamics around a jacket-type foundation structure: Influence of structural configuration and bracing design

This study investigates the hydrodynamic behavior around jacket-type foundation structures with different structural designs subjected to steady current. Numerical simulations were carried out using a three-dimensional OpenFOAM model solving the unsteady Reynolds-averaged Navier–Stokes equations to examine how inclination, X-bracing, and horizontal bracing influence the flow and near-bed hydrodynamics. For this purpose, structures with and without bracing, and with and without inclined piles, were compared. The results show that the flow around inclined configurations recovers faster downstream and exhibits a broader vertical distribution, while straight configurations form deeper and more persistent wakes. The presence of braces enhances local turbulence and near-bed shear, with X-braces strengthening downflow along the inner sides of the piles and redistributing shear toward the sides and wake regions. Horizontal braces create localized high-shear zones near brace–pile junctions and slightly increase turbulence close to the bed. Inclined configurations produce higher drag coefficients than straight ones. These results demonstrate that structural inclination and bracing substantially affect flow behavior, such that ignoring these features in design simulations could lead to misjudgments. Therefore, they should be included in design strategies. • Systematic CFD study on the effects of pile inclination and bracing design. • Inclination promotes faster wake recovery and vertical flow redistribution. • X-bracing strengthens inner-pile downflow and intensifies near-bed shear stress. • Inclined jackets exhibit higher drag coefficients than straight pile groups. • Bracing enlarges inter-pile regions of elevated bed shear stress within the footprint.