Author(s): Gilles Belaud; Xavier Litrico
Linked Author(s): Gilles Belaud
Keywords: Potential flow; Orifice; Open-channel; Velocity field; Sediment diversion
Abstract: This paper presents an analytical solution of the velocity field generated by an orifice located on the side of an open channel. Under the inviscid and irrotational assumption, the 3-dimensional velocity field generated by a rectangular orifice can be derived analytically by superposition of infinitesimal sinks. In rectangular open channels, the free surface and the bed are taken into account by an infinite series of virtual sinks. This solution can be superposed to a uniform velocity field, and the path lines crossing the orifice are accurately determined. This method is used to determine the dividing surface for the flow withdrawn by a rectangular side orifice in an open-channel, then the sediment concentration in the diverted flow. The results are consistent with those obtained by resolution of the 3D Navier-Stokes equations closed by a standard k − ǫ model. Finally, we analyze the effect of the orifice characteristics on the sediment concentration in the diverted flow. We show that its position from the bottom and the withdrawn discharge are the most sensitive parameters. K eywords: potential flow, orifice, open-channel, velocity field, sediment diversion
Year: 2007