Print Email Facebook Twitter Air pocket removal from downward sloping pipes Title Air pocket removal from downward sloping pipes Author Pothof, I.W.M. Clemens, F.H.L.R. Faculty Civil Engineering and Geosciences Department Water Management Date 2012-12-31 Abstract Air-water flow is an undesired condition in water pipelines and hydropower tunnels. Water pipelines and wastewater pressure mains in particular are subject to air pocket accumulation in downward sloping reaches, such as inverted siphons or terrain slopes. Air pockets cause energy losses and an associated capacity reduction. Despite its practical relevance, many phenomena associated with airwater flow in downward sloping pipe reaches are still poorly understood. Deltares and Delft University of Technology have investigated the co-current flow of air and water in twelve different large-scale facilities. Pothof and Clemens have recently developed a numerical model for the total air discharge by flowing water in downward sloping pipes. The model has been validated against the experimental data on co-current air-water flow and available literature. This paper presents new experimental data on the breakdown and removal of large air pockets. The experimental results are compared with the numerical model. The observed disagreement is analysed and discussed. The main conclusion is that the numerical model predicts the air pocket breakdown rate with reasonable accuracy. Subject air discharge, air pockets, downward pipe angle, pipe flow, two-phase flow, wastewater To reference this document use: http://resolver.tudelft.nl/uuid:16f5189d-02f9-41d5-8ef0-7eebedbb71bc Publisher IAHR/IWA Joint Committee Urban Drainage, Working Group on Data and Models Source 9th International Conference on Urban Drainage Modelling, Belgrade, Serbia, 4-6 September 2012 Part of collection Institutional Repository Document type conference paper Rights (c) 2012, Pothof, I.W.M., Clemens, F.H.L.R. Files PDF 286916.pdf 532.8 KB Close viewer /islandora/object/uuid:16f5189d-02f9-41d5-8ef0-7eebedbb71bc/datastream/OBJ/view