Comparing the transitional behaviour of kaolinite and bentonite suspension flows

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Baas, JH ; Best, JL ; Peakall, J (2016)
  • Publisher: Wiley

Past research has demonstrated the dramatic effects that variations in suspended clay can have on the properties of flow by producing a range of transitional flows between turbulent and laminar states, depending on clay concentration and fluid shear. Past studies have been restricted to kaolinite flows, a clay mineral that has relatively weak cohesive properties. This paper extends these studies to suspension flows of bentonite, a clay mineral that attains higher viscosities at far lower volumetric concentrations within a flow. The results show that the types of transitional flow behaviour recognized in past studies can also be found in bentonite suspension flows, but at lower suspended sediment concentrations, thus demonstrating an even more dramatic effect on flow properties, and potentially on sediment transport and resulting bed morphology, than kaolinite flows. The paper proposes new stability diagrams for the phase space of bentonite flows and compares these to past work on kaolinite suspension flows. These new data suggest that the transitional-flow Reynolds number can be used to delineate the types of transitional flow across different clay types and assess modern and ancient clay-suspension flows.
  • References (35)
    35 references, page 1 of 4

    Alexander J, Barclay J, Sušnik J, Loughlin SC, Herd RA, Darnell A, Crosweller S. 2010. Sediment-charged flash floods on Montserrat: the influence of synchronous tephra fall and varying extent of vegetation damage. Journal of Volcanology and Geothermal Research 194: 127-138.

    Amos CL, Droppo IG, Gomez EA, Murphy TP. 2003. The stability of a remediated bed in Hamilton Harbour, Lake Ontario, Canada. Sedimentology 50: 149-168.

    Baas JH, Best JL. 2002. Turbulence modulation in clay-rich sedimentladen flows and some implications for sediment deposition. Journal of Sedimentary Research 72: 336-340.

    Baas JH, Best JL. 2008. The dynamics of turbulent, transitional and laminar clay-laden flow over a fixed current ripple. Sedimentology 55: 635-666.

    Baas JH, Best JL. 2009. On the flow of natural clay suspensions over smooth and rough beds. ERCOFTAC Bulletin 78: 32-37.

    Baas JH, Best JL, Peakall J. 2016. Predicting bedforms and primary current stratification in cohesive mixtures of mud and sand. Journal of the Geological Society 173: 12-45. DOI:10.1144/jgs2015-024.

    Baas JH, Best JL, Peakall J, Wang M. 2009. A phase diagram for turbulent, transitional, and laminar clay suspension flows. Journal of Sedimentary Research 79: 162-183.

    Best JL, Leeder MR. 1993. Drag reduction in turbulent muddy seawater flows and some sedimentary consequences. Sedimentology 40: 1129-1137.

    Best JL, Kirkbride AD, Peakall J. 2001. Mean flow and turbulence structure of sediment-laden gravity currents: new insights using ultrasonic Doppler velocity profiling. In Particulate Gravity Currents, McCaffrey WD, Kneller BC, Peakall J (eds). IAS Special Publications 31. International Association of Sedimentologists (IAS): Gent; 159-172.

    Caldwell DR, Chriss TM. 1979. The viscous sublayer at the sea floor. Science 205: 1131-1132.

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