Stability criteria of Samara-like decelerator in unsteady transitions

Abstract

The physics behind the transitions of natural Samaras, or the bio-inspired counterparts, to steady autorotation has been unclear. Theoretical and experimental investigations explore the inertial and aerodynamic characteristics required to guarantee stable transitions of an artificial Samara-like decelerator from chaotic tumbling motions to azimuthal autorotation. A non-dimensional inertial criterion is proposed, which is in accord with experiments.