Mechanical engineering researchers Mark Jankauski and Erick Johnson converse in their lab, where they conduct experiments to improve the ability to design small, flapping wings. MSU Photo by Adrian Sanchez-Gonzalez.
Drones being used in almost every industry segment these days for aerial imagery are growing in popularity and becoming smaller. But that miniaturization, which produces palm sized drones has caused them to get caught up in the laws of physics.
Spinning rotor blades like those of a helicopter can be downsized only to an extent before air friction overtakes lift force, causing the tiny motors to overheat and fail. With applications for tiny drones like monitoring natural gas pipelines for leaks or darting among blossoms to help pollinate crops in mind, engineers are taking inspiration from flapping wing flight of hovering insects.
Mark Jankauski, assistant professor in the Department of Mechanical and Industrial Engineering at Montana State University’s Norm Asbjornson College of Engineering says that ‘Flapping wings can scale down almost indefinitely’ and still produce sufficient lift force.
But according to Jankauski, who specializes in the field creating artificial versions of the insects’ intricate designs is another matter since the precise mechanics of flapping wings remain poorly understood. 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.
“There is still a lot of work to be done before (flapping wings) are a viable technology for an application,” Jankauski said. “This is a jumping off point.”
MSU assistant professor of mechanical engineering Erick Johnson who is Jankauski’s partner on the project and specializes in the computer simulation models of how wing like structures interact with fluids, including air says, “My models take days or weeks to run’ on an average computer, by comparison, the models that the researchers develop will be almost instantaneous,” he said, adding that “it’s a fascinating field to be in.”
Once this is accomplished that will mean finding approximations for the complicated equations that would otherwise be crunched by the computer models. To do that, Jankauski and Johnson will make detailed measurements of actual flapping wings.
Researchers use a device in their lab, that can precisely bend wing replicas to create detailed geometric maps of how wings respond to various forces naturally. They will also be experimenting with other testing rigs that replicate and measure flapping insect flight, Jankauski says.
Eventually the new models could allow designers to consider thousands of possible wing designs and get quick feedback about which would best serve to lift and maneuver tiny drones. According to Jankauski the models could also be used to help control drones’ flight by calculating the needed wing pitch or flapping speed.
“There’s an absolute wealth of knowledge to be gained about the world through the study of insects and how they interact with their environments,” Jankauski stated. The project will likely contribute to a growing field of science that explores the extraordinary features of biological fliers more generally.