Phys.Org
https://phys.org/news/2019-06-drones-insects.html

By The unmanned aircraft known as drones, used by hobbyists, researchers and industry to take aerial images and perform other tasks, are growing ever more popular—and smaller. But that miniaturization, which has produced drones that fit in a person's palm, has started to bump into the laws of physics.

Spinning rotor blades like those of a helicopter can be downsized only so much before air friction overtakes lift force, causing the tiny motors to overheat and fail. That's why engineers, in an effort to develop tiny drones that could one day monitor natural gas pipelines for leaks or even dart among blossoms to help pollinate crops, are increasingly interested in the flapping wing flight of hovering insects.

Nature has suggested what scientists are beginning to understand in theory: "Flapping wings can scale down almost indefinitely" and still produce sufficient lift force, said Mark Jankauski, assistant professor in the Department of Mechanical and Industrial Engineering at Montana State University's Norm Asbjornson College of Engineering.

But creating artificial versions of the insects' intricate designs is another matter. That's because the precise mechanics of flapping wings remain poorly understood, according to Jankauski, who specializes in the field.

Now, backed by a three-year grant of $370,000 from the National Science Foundation, Jankauski is leading a project to map the physics of flapping flight in new ways, including with more efficient analytical models that could dramatically simplify the process of designing the wings.

Read on: https://phys.org/news/2019-06-drones-insects.html