Benny Kuan

CFD Modelling of the Effects of Operating Parameters on the Spreading of Liquids on a Spinning Disc

A novel dry slag granulation process based on a spinning disc is being developed by CSIRO. This process utilises centrifugal force to break up molten slag into droplets, which are then quenched into solidified granules by a flow of cold air. In this process the sensible heat of slag is recovered as hot air. In the present work, a previously developed steady-state, two-dimensional and multiphase CFD model was applied to perform parametric numerical experiments to investigate the effects of a number of parameters on the liquid film thickness at the disc edge, which included liquid mass feeding (pouring) rate, disc spinning speed, disc radius, liquid viscosity, density and surface tension. The modelling results were compared with experimental data and were found to be in good agreement. To reduce the number of simulations needed, Box and Behnkens fractional factorial design of numerical experiment was adopted. Furthermore, in order for the modelling results to be applicable to atomisation of different liqui...

CFD Simulation of Single-Phase and Dilute Particulate Turbulent Flows in 90° Duct Bends

Single-phase and two-phase (gas-solid) turbulent flow calculations are performed for 90° duct bends having radii of curvature ranging from 1.5 to 2.0 duct diameter, and with either a square or circular cross-section. The considered flow Reynolds number is between 6×104 and 3×105 , and the particulate flows examined pertain to two different solid mass loading ratios: 1.5×10−4 and 0.33. Numerous turbulence models have been utilized to simulate the turbulent fluid motion within the duct bend while particle trajectories are calculated on the basis of a Lagrangian approach. Reasonable agreement with the experimental data is achieved for the continuous phase in the cases tested. In contrast, significant disparities with the measurements arise in particle tracking calculations, especially in regions where particle rope dispersion is predominant. Results of this investigation indicate the need for more experimental testing of mill-duct flows of similar configuration in order to facilitate a better understanding and modeling of strongly curved gas-solid duct flows.Copyright