Experimental and simulation analyses for synthetic and biodegradable impellers

Computational Fluid Dynamics (CFD) is commonly implemented in industry to perform fluid-flow and heat-transfer analysis, however, rarely used in computational material engineering. The project aim is to select a biodegradable composite for impeller used in conventional domestic extraction fan. The analysis starts with a validation of the experimental values of thrust obtained from different materials used to manufacture impellers tested in a wind tunnel. An identical model was used in the CFD simulation using STAR-CCM+ software. The study compares thrust values of different impellers made from thermoplastic polymer such as Acrylonitrile Butadiene Styrene (ABS), Polylactic Acid (PLA) and composite materials such as Bronze-fill, fibre glass and wood fill composites. The results revealed that composite impellers like Bronze-fill and Glass fibre fill composites perform better in term of thrust than traditional ABS impeller. Also, biodegradable wood fill composite shows competitive alternative to replace the conventional ABS impeller used in fan extraction units. A cost comparison shows that wood-fill composite impeller would be cheaper to manufacture using Polymer Injection Moulding (PIM). A crack growth can be monitor using Acoustic Emission (AE) during solidification of molten plastic.membrane surface were made with an electrochemical approach and the results were used to validate CFD simulations. As good results were obtained with the CFD model (<9% error), it was extrapolated to include the non-Newtonian behaviour of activated sludge.