Wednesday January 17, 2007

Bird-brained Research

Aaron Altman, an assistant professor of mechanical and aeronautical engineering, always is looking for creative ways to get students to reach new heights.

A University of Dayton professor figures what's good for the goose is good for finding more efficient, and thus cheaper, ways of flying aircraft. And what would give a better lesson than something that has flown for millions of years?

Many natural-born flyers, like birds and insects, don't need to be moving forward to fly, according to Aaron Altman, an assistant mechanical and aerospace engineering professor. So, he's sending mechanical birds and insects into wind tunnels, shooting lasers at them and taking high speed photos to see how they generate lift and reduce air resistance, or drag.

Altman said there has been very little change in the way the profession has looked at lift generation for the last 100 years and it may be time for a different perspective even if this line of questioning doesn't yield any improvement.

"But, we would be remiss if we didn't at least ask the questions," said Altman, who has worked on the Airbus A340 and A380. "People think aerodynamics is a mature science. If it were a mature science, we wouldn't be losing so much energy to drag. There is a better way. We apply thermodynamics for ways to save heat and energy, so why not for air?"

Altman said vortices, or air trailing airplane wings in the form of giant tornados, are basically wasted energy. Altman said the cost of air travel could drop, fuel efficiency would increase and planes could fly farther with more people if airplanes could harness that energy.

"Geese flying in formation flap in a more continuous motion and use vortices to their benefit by reducing drag," Altman said. "The answers I'm looking for to recovering this lost energy may lie with the manner in which birds and insects move air over their wings to generate lift. The bigger question is how to do it (in planes) without flapping the wings."

Describing flight basics from the world's most experienced flyers is among the different ways Altman encourages his classes to take unconventional looks at aeronautical engineering.

"Posing unconventional, open-ended problems with no unique solutions better prepares students for a world filled with problems that don't have answers in the back of a book," Altman said.

A recent class looked at ways to launch a rocket off a plane at altitudes around 60,000 feet, despite the fact that air density at that level is a 10th of what it is at sea level. However, doing so would be cheaper than launching a rocket from the ground for a specific range of payloads. The subsequent rocket would take much less fuel, be able to carry more payload and would be much less expensive, Altman said.

Another Altman class worked on developing an inflatable, backpack portable plane, which can be operational in less than five minutes, undetectable from 100 yards and weighs less than 25 pounds. Military troops could send such a craft quickly over a ridge or into a mountainous valley to search for hazards.

Other Altman students have looked into planes that change wing shapes during flight.

For interviews, contact Shawn Robinson at 937-229-3391.