Flight of the bumblebee
19 Apr 2013 by Evoluted New Media
A bumblebee is more stable when it is flying quickly, rather than hovering at slow speeds suggests research published in the Journal of Theoretical Biology.
Researchers in China used a mathematical model to analyse the way bumblebees fly at different speeds. They found that the bumblebee is unstable when it flies slowly or hovers but becomes neutral at medium and high flight speeds.
“Dynamic flight stability is of great importance in the study of biomechanics of insect flight. It is the basis for studying flight control, because the inherent stability of a flying system represents the dynamic properties of the basic system. It also plays a major role in the development of insect-like micro-air vehicles,” said Mao Sun from Bejing University of Aeronautics and Astronautics and co-author of the paper.
The researchers suggest the instability at hovering is mainly due to a sideways wind made by the movements of the wings – what they call a ‘positive roll moment’. When the bees increase the speed of their flight, their wings bend towards the back of their bodies and reduce the effect of the sideways wind, making the flight more stable.
In 1934 scientists suggested that according to the laws of physics, bumblebees shouldn’t be able to fly. French entomologist August Magnan is quoted in Le Vol Des Insects as saying: “First prompted by what is done in aviation, I applied the laws of air resistance to insects, and I arrived at the conclusion that their flight is impossible.”
But this new research looks at the flight of the bumble using quantum mechanics. Average measurements such as wing size and shape, body mass, and upwards and downwards forces were used to make a stability analysis of the bee in mathematically the same way as that for a rigid aeroplane.
“The computational approach allows simulations of the inherent stability of a flapping motion in the absence of active control, which is very difficult, even impossible, to achieve in experiments using real insects,” said Sun.
The authors hope the results will be useful in the development of small flying machines like robotic insects.
