GALCIT Colloquium

Unsteady flow control is challenging in many engineering domains. Active techniques are costly, energy-intensive, and heavy, while passive approaches often lack robustness in handling complex flow dynamics. Metamaterials are structures with engineered architecture, allowing for catered response behaviors to stimuli. These structures offer a transformative potential for flow control by flow-metamaterial interaction, FMI. FMI could allow engineers to leverage architected structures to produce desired flow responses passively and adaptively. 

To capitalize on this potential, however, we must first identify which classes of metamaterials are most promising for different flow scenarios, and understand how to align the key metamaterial behaviors with the relevant flow length- and timescales to enable favorable flow-structure interplay. This understanding must account for the behavior of the fully coupled flow-metamaterial system, which will generally yield dynamics with distinct time/length scales from those of the constituent flow/structure systems. Obtaining this understanding requires a suite of computational tools capable of predicting and understanding the flow-structure interplay between the targeted complex flows and modern architected structures.

We present some a-la-carte results on these various challenges and opportunities. We discuss some key metamaterial classes that are promising for certain flow behaviors. We share some ongoing development of high-fidelity and resolvent computational tools within an immersed boundary framework, currently without flow-structure interplay but being designed to enable robust, versatile computations between flows and a wide range of metamaterials. Finally, for simplified flow-metamaterial configurations, we discuss efforts to synthesize appropriate dimensionless parameters, expressed in terms of key intrinsic properties of the separate flow/structure systems, that govern the FMI system's behavior.  

*Andres is grateful for funding from AFOSR to perform the presented work.