Verification of numerical study of scour around spur dikes using experimental data

Scour phenomenon around a series of impermeable, nonsubmerged spur dikes has been investigated with both experimental and numerical methods. The experiments were conducted under different states of flow intensity (U/U-cr). The scour geometry was measured with a high-resolution laser bed-profiler (LBP). For the numerical simulation phase, a three-dimensional computational fluid dynamics (CFD) model, namely SSIIM 2.0, was used to compute the sediment transport around the spur dikes. The numerical model was based on the finite-volume method. Two turbulence models, namely k-epsilon standard and k-epsilon with re-normalization group (RNG) extensions, were used to predict turbulence, and the k-epsilon model with some RNG extensions was selected because of its best agreement with the measurements. Furthermore, a variety of grids and empirical sediment transport equations were used to find the best state for simulation of scour around a series of spur dikes. Finally, a comparison between experimental and numerical results was carried out to verify the CFD model.