engleski

Scour around the circular and sqare profile piers

The study shows methodology and results of the conducted local erosion research around the circular and square profile piers under the clear-water condition. Physical and numerical modelling technique has been used to achieve primary goal for determining the depth of the erosion pit, comparing with the results obtained trough application of empirical equations suggested by series of authors. The shape of the pier cross section (circular and square), number of piers in the flow cross section (1, 2, 3) and the flow depth with corresponding velocity were varied. The granulation of applied model sediment is uniform and homogeneous (d=2mm). Basic geometrical features of the physical and numerical model were not changed (except the piers). Based on physical model measurements and numerical model simulations, maximum erosion depths (scour) were determined. Obtained results are compared mutually and with empirical equation results using the same geometric and hydraulic conditions. Numerical simulations have been conducted with the aim of Mike 21fm numerical model based on the finite volume method. The results of the modeling indicate a more pronounced erosion around the circular piers. The empirical equation from Melville (1997) gives the values of erosion pit depth closest to the measurement results on the physical model and the results of numerical model simulations. The highest degree of resemblance with the models results was achieved in the case where three piers were embedded. The results of measurement on physical model are better suited to the results of empirical equation compared to the results obtained by numerical simulations.

local scour, pier , numerical model, physical mod

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