Flow structure at a confluence: experimental data and the bluff body analogy

HERRERO, HORACIO; GARCIA, CARLOS M.; PEDOCCHI, FRANCISCO; GUILLERMO, LÓPEZ; SZUPIANY, RICARDO N.; CECILIA E. POZZI-PIACENZA

JOURNAL OF HYDRAULIC RESEARCH

INT ASSOC HYDRAULIC RESEARCH

Lugar: Madrid; Año: 2016

0022-1686

An experimental characterization of the hydrodynamics of amixing interface at an open channel confluence is presented. In the laboratoryexperiments, both a confluence and a cylinder set-up were studied in order tovalidate the bluff body analogy, which has been proposed to characterize the mixinginterface. The experimental characterization included flow visualization andthe computation of the mean flow field, time scales of the coherent structures,and turbulent kinetic energy. The comparison among the two configurationsconfirms the validity of the analogy as similar features were found for themean flow field and time scales of the coherent structures. However,differences in the length of the stagnation zone, the flow velocity deficit,and the turbulence intensity were observed. These differences should be takeninto account when the bluff body analogy is used to characterize the confluencehydrodynamics and to quantify the mixing at the confluence interface.