Author(s): Javier L. Lara; Pablo Higuera; Inigo J. Losada
Keywords: Cross-waves; Supercritical Flow; Open Channel Bend Flow; VOF modeling; RANS modelling
Abstract: The present work describes the use of a numerical model to deal with supercritical open channel bend flows. The IHFOAM model (ihcantabria. com/IHFOAM), a modified version of Open FOAM model, is used to simulate flow behavior. The model has been modified introducing a new set of boundary conditions to ensure that the flow rate remains constant at the boundary. They also present the advantage of reducing the computational cost by reducing the size of the domain because they are able to deal with changes in the regime close to the boundaries. The model has been also validated for a dam breaking problem with an abrupt bend showing satisfactory results. Finally a practical case is presented, showing the potential of the model to be used as an alternative tool for designing supercritical open channel bend flows. Numerical results are used to assist in the design of the Port of Granadilla (Tenerife, Spain) stormwater cross-section channel. Results showed an increment of almost 1 m in the free surface due to the existence of cross-waves, which could not be detected based on theoretical formulations or vertically integrated numerical models.