The spectrum of animal flight: insects to pterosaurs
Abstract
This paper summarises available data on the geometry and flight characteristics of all types of winged animals, including insects, gliders, birds, bats and pterosaurs. Helicopter momentum stream tube theory has been adapted for the estimation of the upper size limits for flying animals in gliding, hovering, solitary and formation flight, and also of performance quantities such as minimum, cruising and maximum steady airspeeds, manoeuvrability and the energy cost of transport. The stream tube theory can be criticised as an over-simplification of the complex flow fields of flapping-wing flight, but overall agreement with known animal flight characteristics is found to be generally good. The theory suggests that many flight performance quantities depend mainly on only two parameters: the animal mass and wing span. This allows the design of a two-dimensional chart in which each flying animal has a location, and in which contours of size limits and performance quantities may be cross-plotted. Flight simulation, based on the momentum theory, has been used to explore the take-off flight of hypothetical proto-flyers from ground and from perches. The results favour the “trees down” rather than “ground up” theory of vertebrate flight origins.
- Publication:
-
Progress in Aerospace Sciences
- Pub Date:
- August 2000
- DOI:
- 10.1016/S0376-0421(00)00007-5
- Bibcode:
- 2000PrAeS..36..393T