Abstract
This article concerns the turbulent flow of Herschel–Bulkley slurries through circular horizontal pipes; in particular, that of concentrated domestic slurry obtained upon separation of domestic waste water and reduction in the use of water for domestic purposes. Experiments with a rheologically equivalent clay (kaolin) slurry indicated a non-Newtonian behaviour of the Herschel–Bulkley type. A modified wall function was developed to enable the Reynolds-averaged Navier–Stokes simulation of Herschel–Bulkley slurries to estimate the wall shear stress. Despite the accuracy achieved, the use of Reynolds-averaged Navier–Stokes models for an entire waste water system is impractical. Therefore, this article assesses the accuracy of semi-empirical models in estimating frictional losses. It also discusses possible modifications of existing models to encompass Herschel–Bulkley behaviour. An evaluation suggests that most existing models deliver estimates of comparable accuracy; however, the probability of these estimates being reliable, while accounting for experimental errors in quantifying the actual frictional losses, is rather low.
Original language | English |
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Pages (from-to) | 196-213 |
Number of pages | 18 |
Journal | Journal of Hydraulic Research |
Volume | 59 (2021) |
Issue number | 2 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- Domestic slurry
- Herschel–Bulkley
- non-Newtonian
- pipe flow
- Reynolds-averaged Navier–Stokes
- urban hydraulics