Flow-induced oscillations of pitching plates using a cyber-physical experimental setup

Fluid-structural interactions between elastically mounted pitching plates and uniform flow commonly produce instabilities, large amplitude limit cycle oscillations (LCOs) and chaos within certain flow regimes. The abovementioned behaviors are an academic sandbox for unsteady aerodynamic and aeroelastic research. Recent advancements in data-driven methods make setups capable of interacting with algorithms and producing large datasets increasingly necessary.

Here, the dynamics of elastically mounted pitching plates are investigated using a cyber-physical approach. The setup consists of a servomotor that emulates a torsional spring and serves as the elastic axis of a pitching plate in uniform flow. This design allows system structural parameters to be modified via software rather than hardware. Testing is performed in a subsonic wind tunnel (Re ~100,000). Preliminary tests characterize the setup using an inverted flag like configuration with the elastic axis located at the plate trailing edge. The setup's ability to investigate divergence, system dynamics, and unsteady aerodynamic loading is demonstrated by direct comparison with a physical counterpart. Additional tests showcase the setup’s versatility and precision by exploring unique experimental conditions including variable structural damping and non-linear restoring forces, to name a few.