Identifying behavioral parameters for coupled dynamics between a phononic material and an aerodynamic flow

Phononic Materials (PMs) offer powerful opportunities for passive, adaptive flow control by enabling tailored fluid-structure interactions (FSI). In this study, we develop a comprehensive framework to systematically explore key behavioral characteristics of diatomic phononic crystals (DiPnCs), such as effective stiffness, truncation resonance, displacement envelope and unit cell mass, impact the FSI with an aerodynamic flow over a compliant airfoil. Our model features a flat plate with a compliant leading-edge section governed by a grounded DiPnC, embedded via a physics-informed Gaussian deformation profile. By leveraging a strongly-coupled immersed boundary method, we simulate distinct FSI configurations across a structure parametric space. We demonstrate how varying the DiPnC truncation resonance relative to the natural vortex shedding frequency primarily influences the interface dynamics, while also exerting a secondary, yet noticeable, effect on the global wake behavior. This includes the observation that displacement envelopes tuned appropriately can amplify or suppress vortex shedding through nonlinear interactions and second-harmonic generation. This work establishes a tunable and interpretable FSI modeling strategy for PM-equipped aerodynamic systems, offering a foundation for their future use of adaptive, passive flow control applications.