SEDIMENT TRANSPORT MODEL CONSIDERING UNRESOLVED SCALES OF TURBULENCE IN LARGE-EDDY SIMULATION AND ITS APPLICATION TO LOCAL SCOURING DUE TO RUN-UP TSUNAMI

Abstract

  A sediment transport model considering unresolved scales of turbulence in large-eddy simulation (LES) is pro-posed in this study. In the proposed model, an approximate value of an exact flow velocity is calculated from a re-solvable flow velocity in LES, and used in computing a friction velocity. For validation, a three-dimensional two-way coupled fluid-structure-sediment interaction model (FSSM) combined with the proposed model is applied to tsuna-mi-induced local scouring around a square cylinder. The results show that the evolution of a scour hole is predicted reasonably well using the proposed model for coarse numerical cells, and demonstrate the usefulness of the FSSM combined with the proposed model in assessing local scouring under eddy-dominated flow fields.