CFD Simulation of Twin-Pipe Pumping Process for 3D Concrete Printing

The twin-pipe pumping (TPP) technology has been developed to achieve stiffening control of 3D printable concrete when two constituent mixtures are pumped separately and blended via a laminar-based static mixer before extrusion. A drastic phase transition of the combined mixture from liquid-like to solid-like occurs due to accelerated hydration. However, it is still needed to investigate the inline mixing process and the flow behaviour of the fresh material inside the static mixer. In this study, a computational fluid dynamics (CFD) model was formulated by using the volume of fluid (VOF) and particle tracking. The pressure build-up, the velocity profile, and the phase distribution of two fluids in the static mixer were analyzed.