Author(s): Heiko Jens Herrmann; Lauri Anton; Janek Laanearu
Linked Author(s): Janek Laanearu
Keywords: No Keywords
Abstract: The study explains the dynamics of air-water stratified flow in a sloped pipe with constant diameter and restricted ventilation. The air-circulation process in a real-length hydraulic model with realistic diameter is investigated for a water filling case. This study qualitatively analyses the air-circulation process in a large-diameter pipe, to explain the air inflow and outflow situations, which may be relevant for outdoor air quality analysis in urban environments. For this purpose, the 3D Computational Fluid Dynamics (CFD) model, representing the two-phase flow of immiscible fluids, is used. The numerical model flow regime is chosen to be turbulent, and the air and water phases are considered to be incompressible, isothermal and Newtonian fluids. Interface tracking for the air-water flow is resolved by applying the volume of fluid method. The case study demonstrates the ability of the advanced numerical modelling tool to predict air-water interfacial drag and associated air exchange of the collector, which is ventilated through three venting towers.
Year: 2026