Mohsen Karimi

Quantification of numerical uncertainty in computational fluid dynamics modelling of hydrocyclones

Abstract Large Eddy Simulations of the flow through a hydrocyclone are used to demonstrate that the Grid Convergence Index (GCI) is a practical method of accounting for numerical uncertainty. The small values of GCI (

Numerical Investigation on Multiphase Flow Simulation in a Centrifugal Flotation Cell

Taking advantage of the flotation process and the centrifugal force is used to separate valuable minerals from waste in the centrifugal flotation cells (CFC). In this article, the applicability of this separator-concentrator was investigated using computational fluid dynamics (CFD). CFD simulations were performed with FLUENT 6.3 in 2D, and the existing flow field was modeled for three phases including air, water, and solid particles. The numerical predictions show that the rotational velocity of 175 rpm was appropriate for the separation. To validate the predictions, a coal flotation test on optimized conditions, suggested by numerical predictions, was carried out. The comparison of experimental data with the simulation results reveals that there is a specific rotational speed in which no meaningful differences between simulation and experimental data could be found. In the experiments conducted by centrifugal flotation cell, maximum weight recovery of concentrate was 35.5% and minimum ash content in concentrate was 9.3%.

Selection of Suitable Turbulence Models for Numerical Modelling of Hydrocyclones

The capability of Computational Fluid Dynamics (CFD) alternates the interest of researcher from the empirical models into the numerical approaches for studying hydrocyclones. This paper presents a comprehensive survey on the influences of turbulence model options in the 3D simulation of the hydrocyclone flow pattern. The required grid resolution was selected through a grid independency study. Four categories of turbulence models involving models based on the Boussinesq hypothesis, the Reynolds Stress Model (RSM), the Large Eddy Simulation (LES) model, and the Detached Eddy Simulation (DES) model were investigated for prediction of velocity components within the hydrocyclone. The methodology was validated by experimental data. The results confirm that both RSM and LES models are efficient turbulent model choices for the simulation of swirling flow of hydrocyclones.