Print Email Facebook Twitter 3D CFD Study of Scour in Combined Wave–Current Flows around Rectangular Piles with Varying Aspect Ratios Title 3D CFD Study of Scour in Combined Wave–Current Flows around Rectangular Piles with Varying Aspect Ratios Author Dutta, Debasish (Indian Institute of Technology Kharagpur) Afzal, Mohammad Saud (Indian Institute of Technology Kharagpur) Alhaddad, S.M.S. (TU Delft Offshore and Dredging Engineering) Date 2023 Abstract This study utilizes three-dimensional simulations to investigate scour in combined wave–current flows around rectangular piles with various aspect ratios. The simulation model solves the Reynolds-averaged Navier–Stokes (RANS) equations using the k–ω turbulence model, and couples the Exner equation to compute bed elevation changes. The model also employs the level-set approach to realistically capture the free surface, and couples a hydrodynamic module with a morphological module to simulate the scour process. The morphological module employs a modified critical bed shear stress formula on a sloping bed and a sand-slide algorithm for erosion and deposition calculations in the sediment bed. To validate the numerical model, simulations are conducted in a truncated numerical wave tank with the Dirichlet boundary condition and active wave absorption method. After validation, the numerical model is used to investigate the effect of aspect ratio and the Keulegan–Carpenter (KC) number on scour depth in a combined wave–current environment. The study finds that the normalized scour depth is highest for a rectangular pile with an aspect ratio of 2:1 and lowest for an aspect ratio of 1:2. The maximum normalized scour depth (S/D) for aspect ratios of 2:1 are 0.151, 0.218, and 0.323 for KC numbers 3.9, 5.75, and 10, respectively, whereas the minimum normalized scour depth (S/D) for aspect ratios of 1:2 are 0.132, 0.172, and 0.279. Additionally, the research demonstrates that the normalized scour depth increases with an increase in the KC number for a fixed wave–current parameter (Ucw). Subject CFDREEF3Dlocal scourwave–current flowrectangular cylinder To reference this document use: http://resolver.tudelft.nl/uuid:1f90683c-525f-4539-a449-5b822ca99890 DOI https://doi.org/10.3390/w15081541 ISSN 2073-4441 Source Water, 15 (8) Part of collection Institutional Repository Document type journal article Rights © 2023 Debasish Dutta, Mohammad Saud Afzal, S.M.S. Alhaddad Files PDF water_15_01541.pdf 11.29 MB Close viewer /islandora/object/uuid:1f90683c-525f-4539-a449-5b822ca99890/datastream/OBJ/view