Influence of permeable bed and channel width on turbulent characteristics in inclined open channel flows

Abstract

For the investigation of the influence of the kind of the different permeable bed and channel width in inclined open channels, a series of laboratory experiments were performed. Experiments were conducted in two channels with different widths. The permeable bed is simulated using four different types of porous bed: (a) porous filters, (b) rods bundle, (c) grass vegetation, and (d) gravel bed. All the permeable beds have the same thickness and the same porosity. These conditions are similar to environmental flows. Laboratory experiments were used for the calculation of the turbulent velocity profiles and the turbulent characteristics of the flow (turbulent intensities and turbulent shear stresses). The measurements were obtained using a two-dimensional Particle Image Velocimetry. Measurements of velocity were taken for inclined channels for different slopes S and for the same three different heights h′ over the permeable bed. The results indicate that the presence of different kinds of the permeable bed and the different widths of the channel influence the turbulent characteristics of the flow. © 2016 Indian Society for Hydraulics.