Author(s): Carsten Thorenz
Linked Author(s): Carsten Thorenz
Keywords: No Keywords
Abstract: Air entrainment and dispersed bubble transport can play an important role in the hydraulic behaviour of navigation locks during filling operations. When strong turbulence or local plunging phenomena occur, air can be introduced into the water body in the form of bubbles that rise, diffuse, and interact with the surrounding water. These processes alter the mixture density and thus influence momentum exchange and free-surface dynamics. Bubbles can coalesce and form larger air pockets, which can violently erupt from the water. This potentially endangers both vessels during the locking process and the operational staff of the lock. As a consequence, air entrainment is generally avoided in the planning process of locks with deep culvert systems (PIANC 2025). In this work, a modelling approach is presented that aims to model the flow of air and water on the large scales of a navigation lock. Conventional interface-capturing approaches based purely on the Volume of Fluid (VoF) method do not adequately capture these effects, because dispersed bubbles fall well below the grid resolution and a sufficiently fine grid is not feasible for the spatial scales encountered at a navigation lock. The modeling approach applied here couples Large-Eddy Simulation (LES) concepts with a sub-grid scale model for air bubble transport. Preliminary results for the phenomenological validation of air-water flows at the navigation lock in Hannover-Anderten (Germany) are presented.
Year: 2026