Author(s): Aaron Kreji; Simon Tait; Melika Gul
Linked Author(s): Simon Tait
Keywords: Wall bounded turbulent flows; Free surface turbulent flows; Partially-filled pipe flows; Turbulent flows
Abstract: Gravity-driven partially-filled pipe flows are significantly different from pressure-driven fully-filled pipe flows. As such, strong secondary currents are induced due to the presence of a free-fluid surface in a partially filled-pipe flow. These secondary currents manifest themselves in the form of counter-rotating vortices that can extend the entire flow depth. Despite their significance in various engineering applications, particularly in sewer networks and urban drainage systems, partially-filled pipe flows have remained under explored. Hence, it is unclear how these secondary currents impact the overall turbulent flow behaviour and resulting mass, momentum and energy transport mechanisms as well as local wall friction. Addressing this critical knowledge gap, this study investigates secondary currents in a partially-filled pipe flow for a range of water depth (0.22D−0.6D, where D is the pipe diameter), and Reynolds number (Re) = 1000 −3200) with a particular focus on the interplay between secondary currents, turbulent flow and local wall friction. The analyses are based on experimental data that is acquired with stereoscopic particle image velocimetry and hot-film anemometry. All experiments are conducted in the gravity-driven pipe flow facility at the Integrated Civil and Infrastructure Research Centre of the University of Sheffield. The pipe has a length and diameter of 20 m and 0.29 m, respectively.
Year: 2025