Sewer cleaning with the means of flushing offers the possibility to place sewers free of deposit if flushing waves are generated continuously or quasi-continuously by suitable flushing devices. Numerical investigations should be carried out regarding different hydraulic circumstances because sewer networks consist of various compounds with complex geometries e.g. cross-section alignment or special structures. To accomplish a stable and successful operation of flushing devices it seems necessary to use different level of approximation on modelling flushing waves. Thereby both accuracy and running-time of simulations with numerical models will be optimized. This paper presents differences and similarities of the simulation results of a one-dimensional and a three-dimensional model of flushing wave within a big sized sewer. As assumed the one-dimensional model becomes less accurate when the complexity of the geometry increases. The three-dimensional model shows an underestimation of velocity and bottom shear-stress at the flushing head due to energy losses within the water body. Contrary, the one-dimensional model overestimates bottom shear-stress at the flushing head because of a stationary basic approach which is used. However, real highly resolved measurements of bottom shear-stresses are required to confirm the results in detail.
Research Article|June 01 2007
Impact of the Level of Approximation on Modeling Flushing Waves
Water Practice and Technology (2007) 2 (2): wpt2007036.
P. Staufer, J. Dettmar, J. Pinnekamp; Impact of the Level of Approximation on Modeling Flushing Waves. Water Practice and Technology 1 June 2007; 2 (2): wpt2007036. doi: https://doi.org/10.2166/wpt.2007.036
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