Harnessing Phononic materials for Unsteady Aerodynamic flow control*

Challenges involved with active actuation have motivated the need for flow-control paradigms that can passively adapt to the unsteady flow dynamics. We focus on harnessing phononic materials towards this aim. Phononic materials are architected materials with frequency-dependent characteristics that arise from their periodic and/or resonant microstructure. These frequency-dependent dynamics offer significant potential in the passive control of unsteady aerodynamic processes which inherently contain flow structures with characteristic frequency content. The phononic material is modeled as a nonuniform bi-layer flat plate (i.e., having two periodically repeating materials) using linear Euler Bernoulli beam theory. We perform high-fidelity 2D numerical simulations of flow past the phononic flat plate at an angle of attack of 15 degrees and a Reynolds number of 1000. We identify phononic material parameters that lead to lift/drag benefits compared with a rigid flat plate and characterize the FSI interplay between the vortex shedding phenomena and the plate vibrations. Where relevant, connections between the performance benefits and the phononic material regime (e.g., the bandgap) will be drawn.