Author(s): Alemu Tezera Dessie; Saeed Hashemikia; Pedro Ramos; Greet Deruyter; Tom De Mulder

Linked Author(s): Alemu Tezera Dessie

Keywords: Open-channel confluence; Rigid-lid; SPTV; VOF

Abstract: In a T-shaped, lab-scale open-channel confluence, time-averaged surface velocities are acquired with Surface Particle Tracking Velocimetry (SPTV) in a Froude-scaled experiment of the dataset by Weber et al. (2001). The performance of two 3D numerical models, adopting a distinct free surface treatment, is assessed against these experimental surface velocity data and available free surface elevation measurements. The model adopting the Volume of Fluid (VOF) method overestimates the length of the water level depression zone, in contrast to the model adopting a curved rigid-lid. Both models agree well with the measured surface velocities when these are relatively large, but show discrepancies, also mutually, in zones with a small transversal velocity component. The model adopting the VOF produces longer and slightly wider zones with reverse flow at the surface and recirculating motions near the surface, in comparison to the rigid-lid-based model. Also the separated flow zone near the surface is slightly smaller for the latter model.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1978-cd

Year: 2025