Research on Flow Simulation and Design Optimization of Large-size Fused Deposition Manufacturing Printing Nozzle
Abstract
Fused deposition modeling (FDM) technology is widely adopted in production and typically uses 0.4 mm nozzles for precision printing, but there is little research on large-bore nozzles. Therefore, this paper designs a nozzle with a nozzle diameter (d) of 3 mm, and uses orthogonal design combined with Polyflow to systematically study the influence of nozzle structural parameters on the flow characteristics of polylactic acid (PLA) melt. Using Range Analysis Method, the significance of each parameter was clarified, and the best nozzle structure combination was obtained by optimization using Genetic Algorithm (GA). It was found that, among the structural parameters, liquefier diameter (D) has the most significant effect on the melt flow characteristics, and its increase can enhance the outlet velocity but reduce the melt viscosity; outlet length (L3) has the greatest effect on the pressure distribution, and the pressure decreases with the increase of L3; and the effect of the nozzle length (L2) is relatively small. The optimized nozzle structure (D = 15 mm, L2 = 23-24 mm, L3 = 7 mm) achieves better overall performance. The results of this research can provide a certain theoretical basis for the design of large-bore nozzles for industrial-grade FDM equipment.