The Effect of Rheology Model of an Activated Sludge on to the Predicted Losses by an Elbow

  • Péter Csizmadia Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, H-1111 Budapest, Műegyetem rkp. 3., Hungary https://orcid.org/0000-0001-5490-6383
  • Sára Till Department of Hydrodynamic Systems, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, H-1111 Budapest, Műegyetem rkp. 3., Hungary https://orcid.org/0000-0002-3806-198X

Abstract

This study presents a numerical investigation of flow and rheological behaviour of activated sludge. These materials are usually driven by pumps in wastewater treatment plants. Because of the correct sizing of the pipeline systems, which is of great importance from the point of view of efficiency, the friction losses and loss coefficients of the components have to be known. These are well-known in the case of Newtonian fluids but few data are available if the rheological properties are non-Newtonian. Three non-Newtonian models (Ostwald, Bingham, Herschel-Bulkley) are investigated related to the friction factor of a straight pipe, the loss coefficients of an elbow and to the pressure drop on this element. For our study the rheological data were used from the literature, where the same sample origin was diluted or concentrated to achieve three different TSS (total suspended solids) contents for the same sludge (7.4 g/l; 6.2 g/l; 3.6 g/l). Moreover, modified Reynolds-number definitions are tested related to the non-Newtonian models in the case of the laminar, transition and turbulent regions.

Keywords: activated sludge, CFD simulation, loss coefficient, non-Newtonian flow, rheological parameters
Published online
2018-09-17
How to Cite
Csizmadia, P. and Till, S. (2018) “The Effect of Rheology Model of an Activated Sludge on to the Predicted Losses by an Elbow”, Periodica Polytechnica Mechanical Engineering, 62(4), pp. 305-311. doi: https://doi.org/10.3311/PPme.12348.
Section
Articles