Numerical study on flow around partially buried two-dimensional ribs at high Reynolds numbers

Abstract

Numerical simulations of flow around wall-mounted two-dimensional (2D) ribs with a rectangular cross-section that represent a simplified model of partially buried cubic artificial reefs on the seabed with different normalized heights of the structure (H/D) subjected to a boundary layer flow at different Reynolds numbers (Re) with different normalized thicknesses of the boundary layer (δ/D), are carried out in the present study. Here D is the characteristic length of the flow and is set as the width of the rectangular cross-section in the present study. The hydrodynamic quantities of the flow on the partially buried ribs are studied by using 2D Reynolds-averaged Navier-Stokes (RANS) equations with the k–ω shear-stress transport (SST) turbulence model. By comparing the simulation results with the published experimental measurements, it can be concluded that the RANS model with the k–ω SST turbulence model can provide satisfactory numerical results. Moreover, parametric studies have been carried out to investigate the effects of Re, δ/D and H/D on the hydrodynamic quantities, i.e. the drag coefficient Cd, the lift coefficient Cl, and the recirculation length xR/D of the wake behind the structure and the results are discussed systematically. The results indicate that the hydrodynamic quantities Cd, Cl and xR/D decrease with the decreasing H/D.