Turbulent structure in uniform inclined open channel flow over different rough porous beds

Abstract

In this study the effects of the different rough porous beds in an open inclined channel are studied experimentally for impermeable and permeable porous bed. For the simulation of porous bed two different types of permeable bed with the same thickness (s′=3cm) and the same porosity ε=0.70 are used: (a) porous filters and (b) gravel bed. Laboratory experiments were used for the calculation of turbulent velocity profiles. Measurements of velocity were taken for inclined channel for three different slopes (S=−0.002, S=−0.004 and S=−0.006) and for five different flow depths (h=5cm, 7cm, 9cm, 11cm and 13cm). The total discharge Q varies from 0.78 to 1.31l/s. The measurements were obtained using a two-dimensional (2D) Particle Image Velocimetry (PIV). The total discharge was estimated using a calibrated venture apparatus. Results showed that the presence of rough porous bed in inclined open channels influence significantly the turbulent characteristics of the flow in comparison with impermeable open channels with the same slopes.