NUMERICAL SIMULATION ON DEVELOPMENT PROCESSES OF MICRO SCALE SAND WAVES AND FLOW RESISTANCE

摘要

Flow resistance in rivers changes with development or attenuation of sand waves. Therefore, it is necessary to understand how flow resistance varies with transformation of sand beds in order to predict the water surface variations. In this study, a numerical model to reproduce the formation processes of micro scale sand waves and flow resistance was developed. A depth averaged flow model taking into account the effects of vertical acceleration and a non-equilibrium sediment transport model are combined. Calculated results on the temporal development processes of sand waves, the shape characteristics of dunes and, finally the flow resistance are compared with previous experimental and theoretical studies.