Aug 05, 2022 21:00:00

It turns out that the bird is flying while switching between 'stable flight mode' and 'fighter mode'

Starting with Leonardo da Vinci, who drew inspiration from birds and drew blueprints of

flying airplanes , human beings have been studying the flight mechanism of birds flying in the sky since the dawn of history, but even today there are still unsolved mysteries. much is left. A previously neglected study of the center of gravity and posture of birds in flight has shown that some birds control both stability and instability in flight.

Birds can transition between stable and unstable states via wing morphing |
https://doi.org/10.1038/s41586-022-04477-8

Geometric Analysis Reveals How Birds Mastered Flight | Quanta Magazine
https://www.quantamagazine.org/geometric-analysis-reveals-how-birds-mastered-flight-20220803/

Birds flying in the sky can fly slowly with their wings spread, or they can fly agilely, such as making abrupt changes in direction. In a 2001 paper laying out a basic theory for why birds can fly stably in all situations, authors Graham Taylor and Adrian Thomas wrote, ``Birds can fly stably. This is due to the combination of 'inherent stability' and 'controllability' that actively responds to disruptive forces.'

Impressed by this research, the research team of Christina Harvey and others at the University of Michigan wanted to formulate the mechanism of stable flight of birds, and embarked on research focusing on the `` inertial characteristics '' of birds. Inertial properties are related to the mass and its distribution of an object, and are a factor that has not been given much attention in bird research, which emphasizes aerodynamic properties mainly based on hydrodynamics.

Mr. Harvey and others who started research immediately ordered 36 frozen specimens of 22 species of birds from the museum, measured the length, weight, wingspan, and bent and stretched the wings by hand to check the range of motion. did. Then, we developed new modeling software that expresses parts such as wings, bones, muscles, skin, and wings as a combination of geometric shapes.

by Jasmin CM Wong

Furthermore, in expressing controllability and stability in mathematical formulas, Mr. Harvey et al. calculated the

static stability margin , which is the distance between the center of gravity of the bird and the neutral point. For example, if the neutral point of a bird in flight is behind the center of gravity, the bird is stable, and if it is in front, it is unstable. Instability also means that movements are more variable in the air, so a certain amount of instability is also necessary for a bird to be agile in the air.

by Samuel Velasco/Quanta Magazine

As a result of analyzing 22 species of birds with the model developed by the research team, one bird is completely unstable, four birds are completely stable, and stable flight and unstable by deforming the wings 17 species of birds were found to be able to switch between different flight modes. Mr. Harvey said about this result, 'The bird can go back and forth between a fighter-like style and an airliner-like style.'

Somersaults and swoops, which birds are good at, are not so necessary for passenger aircraft, but it is expected to help improve the maneuverability of unmanned aerial vehicles such as drones that are capable of drastic maneuvers. Therefore, the research team of Mr. Harvey and others plans to gather students who are interested in the field of engineering in parallel with advancing basic research on birds in the future.