title: Intrinsic stability of a body hovering in an oscillating airflow.
abstract: We explore the stability of flapping flight in a model system that consists of a pyramid-shaped object hovering in a vertically oscillating airflow. Such a flyer not only generates sufficient aerodynamic force to keep aloft but also robustly maintains balance during free flight. Flow visualization reveals that both weight support and orientational stability result from the periodic shedding of vortices. We explain these findings with a model of the flight dynamics, predict increasing stability for higher center of mass, and verify this counterintuitive fact by comparing top- and bottom-heavy flyers.
authors.affiliation: Applied Mathematics Laboratory, Courant Institute, New York University, New York, New York 10012, USA.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Leif
authors.initials: L
authors.lastname: Ristroph
authors.forename: Annie
authors.initials: A
authors.lastname: Weathers
authors.forename: Stephen
authors.initials: S
authors.lastname: Childress
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D032701:Biomimetics / Q000379:methods; D005426:Flight, Animal; D007313:Insecta; D008954:Models, Biological; D008962:Models, Theoretical; D014921:Wings, Animal