(38d) Directionally Dependent Fluid Behavior from Uniform Periodic Structures: Influence of Design and Additive Process Parameters

Additive manufacturing has enabled the realization of constructs like periodic lattice structures, which are wide-ranging in their design and application. In a typical scenario, repeat units are patterned to create a macroscopic form for structural applications requiring isotropic or load-optimized performance. More recent chemical engineering applications include these additive-only lattice structures for their utility in heat exchange and process intensification, still largely based on symmetric, uniform repeat units. However, given the various processes and vast design space that additive manufacturing enables, there is an opportunity to take advantage of anisotropy that arises from the additive process or the parameters of the unit cell. Here we investigate the influences of design-stage and process-stage anisotropy on the fluidic performance of additively manufactured structures printed with the Carbon M1 platform. We examine a parametric array of pyramidal unit cell designs based on rotational symmetry, rather than reflection symmetry, and further consider the orientation of the unit cell with respect to print direction. Characterizing the dimensions of as-printed parts, we observe morphology variation based on part orientation and report the resulting effects of orientation and slicing dimension on fluidic behavior. In contrast to geometries with reflection symmetry about the plane normal to flow, pyramidal unit cells show statistically significant differences in pressure gradient in response to changing the direction of airflow across the part. As a result, we show that it is possible to combine the regularity of 3D printed lattices with controlled anisotropy to produce multifunctional parts with the potential to bolster the presence of additive manufacturing in applications relevant to chemical engineering.