A positron emission particle tracking investigation of the scaling law governing free surface flows in tumbling mills
| Autor: | David N. de Klerk, Aubrey Mainza, Indresan Govender, Max C. Richter |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
Environmental Engineering General Chemical Engineering Flow (psychology) Mechanics Tracking (particle physics) 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Shear (sheet metal) symbols.namesake Classical mechanics Free surface 0103 physical sciences Flow conditioning Froude number symbols Particle 010306 general physics Scaling Biotechnology |
| Zdroj: | AIChE Journal. 63:903-913 |
| ISSN: | 0001-1541 |
| DOI: | 10.1002/aic.15453 |
| Popis: | Positron Emission Particle Tracking (PEPT) measurements are used to track the flow of d=5 mm glass beads within a rotating drum fitted with (and without) lifter bars and operated in the cascading and cataracting Froude regimes. After converting the Lagrangian trajectories of a representative radio-labeled glass bead (the tracer) into Eulerian fields under the ergodic assumption, the bed shape and kinematics are extracted for steady, fully developed flow conditions. Notwithstanding the azimuthal wall effects introduced by the lifter bars, we show a linear scaling 〈v〉∝h of the local flowing layer thickness (h) with local depth-averaged velocity 〈v〉 and a constant average shear 〈γ〉∼0.6gd for direct measurements spanning the entire flowing layer (not just the central region), and high Froude regimes (cascading and cataracting) not previously investigated by scaling analysis in the literature. © 2016 American Institute of Chemical Engineers AIChE J, 2016 |
| Databáze: | OpenAIRE |
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