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

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.

Experimental and Numerical Investigation of the Loss Coefficient of a 90° Pipe Bend for Power-Law Fluid

“…The loss caused by the wall friction was subtracted from it but the forward disturbance of the fitting was taken into consideration. It was verified by the authors that beyond 9D the forward impact of the elbow is negligible because there the Δp e changes less than 5 % [28]. Theoretically, the Reynolds number is the ratio of inertial forces to viscous forces; for Newtonian fluids it is given as Re = vDρ/μ.…”

“…With this modification, the friction factor is f = 64 / Re mod for laminar flow conditions, see e.g. [28,37,39]. This evaluation is useful to compare the results of different power-law fluids with the literature.…”

“…Friction losses of abrupt contraction for power-law materials were calculated by Kfuri et al [26]. Several studies numerically examined flows of power law fluids in a bend [27,28].…”

Modeling, instrumentation, automation, and optimization of water resource recovery facilities (Review of 2018 Literature) DIRECT

“…Csizmadia and Till (2018) presented a numerical investigation of plant hydraulic phenomena and studied the effects on total dissolved solids profiles. An InfoWorks Integrated Catchment Modeling hydraulic model was developed, calibrated, and used to model the headworks and wet‐weather storage facilities of a large by Starosta, Gargeya, Ott, Verma, and Davel (2018) who emphasized the need for system‐wide conveyance and treatment facilities flow coordination.…”

A computational study of curvature effect on pressure drop of gas-liquid two-phase flow through 90 degree elbow

“…Also, they obtained the friction factor coefficient of the pipe and the loss coefficient of the short radius curvature elbow namely (R/D=2). Bingham, Ostwald, Herschel-Bulkley are three non-Newtonian samples of study that are examined related to the straight pipes friction factor coefficient, the loss coefficient of the elbow and the pressure gradient that dropped on this part [24].…”