Power reduction and the radial limit of stall delay in revolving wings of different aspect ratio.

ABSTRACT: Airplanes and helicopters use high aspect ratio wings to reduce the power required to fly, but must operate at low angle of attack to prevent flow separation and stall. Animals capable of slow sustained flight, such as hummingbirds, have low aspect ratio wings and flap their wings at high angle of attack without stalling. Instead, they generate an attached vortex along the leading edge of the wing that elevates lift. Previous studies have demonstrated that this vortex and high lift can be reproduced by revolving the animal wing at the same angle of attack. How do flapping and revolving animal wings delay stall and reduce power? It has been hypothesized that stall delay derives from having a short radial distance between the shoulder joint and wing tip, measured in chord lengths. This non-d

SUBMITTER: Kruyt JW 

PROVIDER: S-EPMC4387534 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature