CONICET | Buscador de Institutos y Recursos Humanos

This work presents an experimental investigation on turbulent flow characteristics in a typical gully with reverse flow. Four different flow rates (inlet Reynolds number ranged between 2.8e+04 and 7.4e+04) were characterized in a laboratory facility using an acoustic Doppler velocimeter. A complete signal analysis was carried out in order to identify and remove the influence of errors in acoustic Doppler measurements on the computation of the mean velocity, turbulent kinetic energy and Reynolds stresses. The flow showed a similar pattern between the different analized experimental conditions in terms of mean velocity and turbulent kinetic energy. A macro anticlockwise spanwise-axis vortex was identified based on the mean velocity field in the region encompassed between the upstream wall and the inlet centerline. Maximum mean velocity magnitudes were about 25% of the inlet velocity and characterized the outer flow of the vortex. Higher turbulent kinetic energies were observed at the inlet centerline region with values about 5% of the inlet velocity square. The Reynolds stresses exhibited some anisotropy, which was revealed by both the shear stresses values and by the differences in the normal stresses. Normal stresses were higher than shear stresses with maximum values at the inlet centerline region ($langle uu angle approx$ 3%, $langle vv angle approx$ 5% and $langle ww angle approx$ 2% of the inlet velocity square, respectively).