Effect of Stirrer Design on Particle Distribution of Aluminium Composite in Stir Casting Process Using CFD Simulation

ABSTRACT

In this experimental investigation, a novel approach was developed to produce uniform distribution of reinforcement for the production of MMCs. The Scrap Aluminium Alloy is used as matrix material and the alumina (Al2O3) as reinforcement via the squeeze casting route. The effect of the blade geometry on the distribution of reinforcement in the molten metal inside the furnace is predicted using Computational Fluid Dynamics (CFD) approach. Two different simulation approaches on the experimental setup are performed in this work. The first approach is to optimize the stirrer height from the base of the furnace crucible using Glycerol water solution, which has similar characteristics to the molten aluminium. The second approach is to optimize the stirrer blade such as blade profile and number of blades etc. using CFD. Geometric modelling and meshing are carried out in 3D system using ANSYS FLUENT 18.1. k-ε turbulence model was adapted to incorporate detailed flow structures for multiphase flow. Simulation results proved that the stirrer placed 30 mm above produced better vortex and mixing quality. CFD results through Power number (Np) calculation is made to estimate the power ability of an impeller or stirrer to disperse reinforcement particles into the molten aluminium alloy.