The effect of heterogeneous geometry on steady-state heat transfer in extrusion-based 3D printed structures

The 3D printed buildings constructed using rapid manufacturing techniques provide opportunities for structural optimization and performance design, which are beneficial in meeting the vision of digital and sustainable development of the construction industry. However, there are still many research gaps in the heat transfer of 3D printed buildings, impacting the accurate design of their thermal performance. This study quantifies the effect of heterogeneous geometry on heat transfer in extrusion-based 3D printed structures. The experiment reveals that the nonuniform surface temperature distribution primarily originates from geometrical factors, with heterogeneous physical properties caused by cold joints having little influence. Numerical simulations using equivalent geometric models indicate that the local temperature and the convective heat transfer coefficient of raised surfaces vary periodically, corresponding to surface shape. As surface bulges increase, the overall average heat transfer efficiency of the 3D printed structure decreases, while total surface heat transfer increases. These findings help to understand the effect of heterogeneous geometric properties on the heat transfer process of 3D printed structures, thus providing a reference for the accurate design of 3D printed structures with thermal functions.