Lunchtalk by Dr. Alice Lefebvre

Date: 4th of July 2013

Location: HR N109

Title presentation: “A numerical investigation of flow separation in the lee of bedforms”


Large asymmetric bedforms are a common feature in tidal inlets and rivers. These bedforms strongly influence the over-lying flow by their form roughness, which is mainly caused by energy dissipation associated with flow separation in the lee of the bedform.


The talk will focus on the use the Delft3D numerical model to investigate the flow separation zone. The model set up and validation against lab data will briefly be explained. The results of a systematic study assessing the influence of flow velocity and bedform dimensions on the flow separation length will be shown. Finally, simulations of flow velocities over large compound bedforms in a tidal environment will be used to characterise the influence of flow reversal and bed morphology on the flow separation zone.