Goktepeli, Ilker2025-10-102025-10-1020252228-61602364-1843https://doi.org/10.1007/s40996-025-02002-1https://hdl.handle.net/20.500.13091/10878Hydrodynamic flow structures of a complex bridge pier have been scrutinized in the present study for a value of Reynolds number as Re = 3.87 × 104. Considering reference cases, different turbulence models have been compared with respect to variant flow structures and drag coefficient values obtained for steady and three-dimensional flow. For the pier, the maximum pressure value has been obtained at the point representing the first flow contact. The reason is the flow stagnation indicating the sudden decline of velocity values. Separated flow caused lower pressure region for the elements of the complex bridge pier. As a result of decreasing cross-sectional areas, flow acceleration between the piles has been observed. At the upstream, there are two dominant clusters representing cross-stream velocity components. The direction of rotation is clockwise for positive values while it is vice versa for negative ones. Moreover, drag coefficients have been obtained as 1.16 ≤ C<inf>D</inf> ≤ 1.178 via different turbulence models. Regarding the past results from literature, k-ω SST turbulence model is the most successful one when it comes to the drag coefficient. As a recommendation, the second one is k-ε Realizable turbulence model by the difference of 0.78% for the drag coefficient. The percentage difference of the drag coefficient is 1.47% obtained by Transition SST turbulence model. Similar situation is obvious for the flow characteristics compared to the reference study. © 2025 Elsevier B.V., All rights reserved.eninfo:eu-repo/semantics/closedAccessComplex Bridge PierDrag CoefficientHydrodynamic Flow CharacteristicsReynolds NumberTurbulence ModelArticle10.1007/s40996-025-02002-12-s2.0-105014825303