Wake transition of an unconstrained self-propelled flexible flapping plate

This study numerically investigates the wake transition of an unconstrained self-propelled flexible flapping plate, which can move freely both longitudinally and laterally. Three distinct wake patterns, including symmetric, deflected, and chaotic, are identified quantitatively. The symmetry breaking will be triggered when the cruising and flapping Reynolds number as well as translational kinetic energy reach critical values, which follow some simple scaling laws. it is also revealed that passive lateral oscillation and bending deformation of the plate are two key mechanisms affecting wake symmetry properties.