VALIDATION OF A NUMERICAL MODEL FOR FLOW AND BEDFORM DYNAMICS

Abstract

An explorative study has been carried out within the scope of this paper in order to validate a morphodynamic numerical model with the assessment of model sensitivity to some factors and parameters. The flow model component is a vertical two-dimensional with non-hydrostatic, unsteady free surface flow condition. The flow model has been coupled with sediment transport models. Two different sediment transport approaches have been used, namely Ashida & Michiue’s bedload transport formula and a stochastic pick up deposition formulation for non-equilibrium sediment transport proposed by Nakagawa & Tsujimoto. The model performance has been tasted for different turbulence closures, namely a zero-equation, a standard k-ε and a non-linear k-ε models, in the context of morphodynamic simulation. Model performance has been evaluated for the prediction of temporal variation of flow-depth and boundary shear stress induced by bedform evolution based on experimental measurements.