Drag Reduction of a Circular Cylinder Through the Use of an Architectured Lattice Material

Abstract

Materials with periodic architectures exhibit many beneficial characteristics such as high specific stiffness thanks to the material placement along the stress paths and the nano-scale strength amplification achieved through the use of hierarchical architectures. Recently, the porosity of architectured materials was leveraged to increase the efficiency of compact heat exchangers, and their internal aerodynamics was studied. However, their performance on external aerodynamics applications is generally assumed to be detrimental. Here, we demonstrate that exposing 3D lattice material to the external flow reduced the drag of a circular cylinder when placed at carefully selected angular locations. We tested two configurations with the lattice material installed at the windward and leeward regions. On the one hand, the windward configuration showed a strong Re dependency, with a drag reduction of up to 45% at Re=11E4. On the other hand, the lattice material in the leeward region reduced the drag by 25% with weak Re dependency. Alterations of the lattice material topology had a noticeable effect on the drag reduction in both cases. Adding aerodynamic features to the already proven beneficial structural properties of 3D lattice materials might aid in the development of low-powered automotive, naval, and aerospace vehicles.