The
initial thought that bees flap their wings
up-and-down, or in a way that is reminiscent
of an airplane, is the reason why scientists
were being puzzled by bee flight. Through the
use of high speed cameras and large-scale
winged robots, scientists were able to track
the path of the bees' wings. They found that
instead of flapping rigidly up and down, their
wings twist and rotate in a curving pattern (Jernigan,
2017).
This
curving pattern generates force that is
perpendicular to the wing, which can then be
broken down into 2 components: lift, which is
the upward force, and drag. The pressure
difference between the flow of air on top of
the wings and below the wings generates a net
circular flow around the wing that ultimately
keeps the bees in the air (Dickinson,
2020).
As the air is deflected downwards by the
wings, a leading-edge vortex* (LEV) forms on
the surface of the wings. When the wings flip
over, another LEV develops on the other
surface creating a larger total LEV. These
vortices are like small tornadoes that
generate enough force to make the bee airborne
(Dickinson
et al., 1999).
Bees are able to hover and maneuver around by
manipulating their wing stroke frequency and
their stroke amplitude. By increasing their
wing beat frequency and lessening their stroke
amplitude, bees are able to hover. If they are
carrying pollen, causing an increase in
weight, they would maintain a constant
frequency while increase the stroke amplitude
(Altshuler
et al., 2005).
*Leading-edge vortex:
the front edge of the wings that meets
oncoming air
