EXPERIMENTAL VERIFICATION OF COUPLED ALLUVIAL FLOW MODELING

摘要

The Merits of a coupled numerical model, compared to an uncoupled model, of alluvial flow are experimentally demonstrated. The uncoupled model is the well-known HEC6 sedimentation program and the coupled model is a newly developed non-dimensional model of riverine flow called COUPFLEX. The models are applied to the data obtained from some laboratory tests on river sedimentation carried out exclusively for this comparison. The strong inter-relation between water and sediment components of alluvial flows is recognised in the coupled approach and this gives it advantages over the traditional uncoupled method in which the calculations of the water flow and bed level variations are separated to various degrees. Application of the models to the experimental data, associated with fast flow and sedimentation processes, reveals the preferability of a coupled approach. Simulation of several carefully performed laboratory tests highlights three beneficial aspects of a coupled approach. It was therefore concluded that while computer programs such as HEC6 are useful tools in dealing with most laboratory and field applications, for the development of new commercial computer programs of alluvial flows consideration of the coupled method as opposed to the traditional uncoupled methods seems inevitable.