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A new laboratory-based methodology for prediction of the maximum scour depth in cohesive soil has recently been developed at the University of South Carolina. Because of the absence of field data, a computational fluid dynamics model, FLUENT, is used to test the scale effects associated with such a methodology. The numerical model was first verified against measurements obtained in the laboratory. The numerical results agreed satisfactorily with the measurements. Then, the numerical model was applied to the rock island protecting the main piers of the Cooper River Bridge, located in Charleston, South Carolina. The scour hole created around the island in the laboratory was scaled up and used in the numerical model. The computed bed shear stresses compared satisfactorily with those scaled up from the measurements and the shear stress at which the field sample begins to erode. It was found that the scour depth of 3.7 m represents the equilibrium state, which is similar to the results scaled up from the laboratory experiments. The numerical results showed that the scour depth of 36 m calculated by the HEC-18 approach is significantly overestimated.

En el presente artículo se discute la simulación de flujos en canales abiertos con frentes pronunciados. Los métodos existentes en la literatura para representar este tipo de flujos son el método de las características, el de diferencias finitas, el de elementos finitos y el de volúmenes finitos. Se enuncian las ecuaciones de movimiento para el flujo en canales, promediadas verticalmente (para aguas someras) y transversalmente, haciéndose una breve discusión de las técnicas numéricas. Así mismo, se indican las condiciones iniciales y de contorno necesarias para completar la construcción de los modelos. Finalmente las técnicas anteriores son aplicadas al análisis de algunos problemas de flujo frecuentes en este campo.