An investigation of granular rheology using Positron Emission Particle Tracking
Presented by Mr. Thirunavukkarasu PATHMATHAS on 9 Jul 2014 from 11:30 to 11:50
Type: Oral Presentation
Track: Track F - Applied Physics
We consider the rheological drivers of granular flows comprising mono-sized (5 mm) glass beads in a 300 mm diameter rotating drum operated in the cascading-to-cataracting Froude regime. By combining the inherent frictional nature of particles within a dense flow regime and noting that industrial rotating drums (tumbling mills) are typically characterised by collisional and turbulent stresses, a theoretical expression of the effective friction coefficient is derived, yielding a customised granular rheology for athermal, free surface granular flows. The input data to the model (velocity, solids concentration, pressure and flow depth) are obtained directly from non-invasive measurement using a nuclear imaging technique: Positron Emission Particle Tracking (PEPT). Using the new rheology, we derive the in-situ power dissipation and show that shear stresses drive the energy dissipation in the tumbling mill.
Dr.Indresan Govender, firstname.lastname@example.org, University of Cape Town