Print Email Facebook Twitter Dynamic hydraulic models to study sedimentation in drinking water networks in detail Title Dynamic hydraulic models to study sedimentation in drinking water networks in detail Author Pothof, I.W.M. Blokker, E.J.M. Faculty Civil Engineering and Geosciences Department Water Management Date 2012-12-14 Abstract Sedimentation in drinking water networks can lead to discolouration complaints. A sufficient criterion to prevent sedimentation in the Dutch drinking water networks is a daily maximum velocity of 0.25 m s?1. Flushing experiments have shown that this criterion is a sufficient condition for a clean network, but not a necessary condition. Drinking water networks include many locations with a maximum velocity well below 0.25 m s?1 without accumulated sediments. Other criteria need to be developed to predict which locations are susceptible to sedimentation and to prevent sedimentation in future networks. More distinctive criteria are helpful to prioritise flushing operations and to prevent water quality complaints. The authors use three different numerical modelling approaches – quasi-steady, rigid column and water hammer – with a temporal discretisation of 1 s in order to assess the influence of unsteady flows on the wall shear stress, causing resuspension of sediment particles. The model predictions are combined with results from flushing experiments in the drinking water distribution system of Purmerend, the Netherlands. The waterhammer model does not result in essentially different flow distribution patterns, compared to the rigid column and quasi-steady modelling approach. The extra information from the waterhammer model is a velocity oscillation of approximately 0.02 m s?1 around the quasi-steady solution. The presence of stagnation zones and multiple flow direction reversals seem to be interesting new parameters to predict sediment accumulation, which are consistent with the observed turbidity data and theoretical considerations on critical shear stresses. To reference this document use: http://resolver.tudelft.nl/uuid:4f214373-00ab-4606-aa2b-d89dd5beeb91 DOI https://doi.org/10.5194/dwes-5-87-2012 Publisher Copernicus Publications ISSN 1996-9457 Source http://www.drink-water-eng-sci.net/5/87/2012/ Source Drinking Water Engineering and Science, 5 (1), 2012 Part of collection Institutional Repository Document type journal article Rights © 2012 The Author(s)Creative Commons Attribution 3.0 License Files PDF Pothof_2012.pdf 2.13 MB Close viewer /islandora/object/uuid:4f214373-00ab-4606-aa2b-d89dd5beeb91/datastream/OBJ/view