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Weaver, Dustin Steven

University of British Columbia

This work presents a coupled Computational Fluid Dynamics - Volume of Fluid - Discrete Element Method (CFD-VOF-DEM) framework for turbulent, particle-laden jet flows with a free surface, focusing on flow dynamics relevant to High-Pressure Slurry Ablation (HPSA™) unit. The overarching objective of this study is to develop and ensure the accuracy of the CFD-VOF-DEM model and then use this model in an industrial application to test and develop an optimization protocol. Validation of the CFD-VOF-DEM numerical method for jet flow is performed using high-speed imaging feature tracking and jet spread. Experimental tests using high-speed imaging are performed for particle-laden jets with a free surface within an exit Reynolds number of 135,000-166,000. Numerical simulations are performed with the developed CFD-VOF-DEM solver with an exit Reynolds number of 150,000, a Stokes number of 29.14, and a solids mass fraction of 0.15. The numerical simulations employ the developed CFD-VOF-DEM solver, incorporating an exit Reynolds number of 150,000, a Stokes number of 29.14, and a solids mass fraction of 0.15. Thorough validation is performed to confirm that the simulations accurately replicate the experimental observations of negligible spread, as determined through particle image statistics, and the measurement of jet surface velocity using a feature tracking algorithm in the high-speed imaging experiments. Along with this, the more intricate behavior of the complicated coupling problem is validated by using the extensive available data on two-phase jets with an analysis and issues solved for turbulence modeling in the context of submerged jets. The developed model is then used to focus on the process efficiency of the HPSA™ unit. Specifically, simulations are performed to investigate the effect of the nozzle-to-nozzle distance and nozzle angle on particle collision frequency and particle breakage efficiency in the impingement zone considering generic soft ore. This research offers an approach to greatly improve the design and increase the efficiency of this unique mineral processing unit by demonstrating the machine’s potential for selective ore size reduction, based on particle size and material properties. It also identifies and addresses some of the pitfalls of using a numerical model in an industrial context.

Text

2024-09-06

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89204

Mining Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/