PhD Project title A Methodology for Coupled CFD-DEM Modelling of Particulate Suspension Rheology
(Duration: 2010 to 2015)
Flow properties, or rheology, of particulate suspensions are highly dependent on the properties of the particles suspended within the base fluid (e.g. size, shape and surface properties). To enhance the study of particulate suspensions, a numerical model was created to simulate particulate suspensions. A combination of Computational Fluid Dynamics (CFD) and the Discrete Element Method (DEM) was used to model the fluid and particulate phases respectively. This work develops the methodology that was used to create this model.
This methodology was first tested using CFD models for both a Newtonian fluid, and a non-Newtonian slurry in rheometers of different geometries. Rheograms were reproduced and compared to experimental values. Once the single-phase model had been validated, particles were added to the model by combining CFD and DEM together. Two open source software packages were used. CFD was implemented using OpenFOAM®, and DEM using LIGGGHTS. Coupling software, called CFDEM, was used to couple these two programmes together.
This coupled model is capable of modelling spherical particles in a suspending liquid. DLVO forces have also been included to account for inter-particle forces that arise due to the surface charge on particles. Data for particle volume fractions from 5 to 40% have been generated. Emphasis has been placed on the 20% volume fraction models to investigate various model parameters that could affect solution accuracy (e.g. time step size, coupling interval). The influence of different DLVO potentials (controlled via the zeta potential) was also investigated. Preliminary analysis of the results shows good qualitative behaviour of the model.
Smuts, EM, Deglon, DA and Meyer, CJ. 2012. Methodology for coupled CFD-DEM modelling of particulate suspension rheology. In Proceedings of Ninth International Conference on Computational Fluid Dynamics in the Minerals and Process Industries, Melbourne, 10-12 December. ISBN 978-1-922173-01-0.
Smuts, EM, Deglon, DA and Meyer, CJ, 2012. Methodology for coupled CFD-DEM modelling of particulate suspension
rheology. In Proceedings of XXVI International Mineral Processing Congress, New Delhi, 24-28 September. ISBN 81-901714-3-7.
Smuts E., Deglon D., Meyer C. 2012. Methodology for coupled CFD-DEM modelling of particulate suspension Rheology. Paper presented at the 30th Annual Southern African SAIMM Mineral Processing Conference, Cape Town, 2-3 August 2012.