Bats Inspire 'Micro Air Vehicle’: Scientists To Use Mechanics Of Bat Wings To Create Small Flying Machines
Most of us at some point or the other have been inspired by Batman, the superhero who can fly with his cloak, and wondered what it would be like to fly like a bat. Well, Virginia tech researchers have not quite invented the "cloak" but they have certainly been inspired by bats and other flying creatures to design "micro air vehicles" with flapping wings, according to a press release Tuesday .
Like Us on Facebook
Micro air vehicles are small unmanned flying vehicles, some as small as 15 centimeters. Recently micro air vehicle developers have been studying bats to try and incorporate their flying patterns in these vehicles. Most species of bats have hand membrane wings, which means their fingers are webbed and connected by a flexible membrane. But scientists find it challenging to figure out how bats use their wings to manipulate the air to fly.
Scientists at Virginia Tech studied flight of fruit bats and used experimental measurements of the movements of the bats' wings in real flight. They then used analysis software to see the direct relationship between wing motion and airflow around the bat wing.
"Bats have different wing shapes and sizes, depending on their evolutionary function. Typically, bats are very agile and can change their flight path very quickly - showing high maneuverability for mid-flight prey capture, so it's of interest to know how they do this," explained Danesh Tafti, the William S. Cross professor in the Department of Mechanical Engineering and director of the High Performance Computational Fluid Thermal Science and Engineering Lab at Virginia Tech.
Fruit bats weigh around 30 grams and the size of their single wing is about 17 x 9 cm in length. Bat wings manipulate the wing motion with correct timing to maximize the forces generated by the wing. "It distorts its wing shape and size continuously during flapping," Tafti noted. For example, it increases the area of the wing by about 30 percent to maximize favourable forces during the downward movement of the wing, and it decreases the area by a similar amount on the way up to minimize unfavorable forces. The force coefficients generated by the wing are "about two to three times greater than a static airfoil wing used for large airplanes," said Kamal Viswanath, a co-author of this report.
But this is only the beginning of the researchers' work. "Next, we'd like to explore deconstructing the seemingly complex motion of the bat wing into simpler motions, which is necessary to make a bat-inspired flying robot," said Viswanath. Their aim is to keep the wing motion as simple as possible, but with the same force production as that of a real bat.
"We'd also like to explore other bat wing motions, such as a bat in level flight or a bat trying to maneuvre quickly to answer questions, including: What are the differences in wing motion and how do they translate to air movement and forces that the bat generates? And finally, how can we use this knowledge to control the flight of an autonomous flying vehicle?" said Tafti.
Source: Viswanath, K. Tafti, DK. "Straight-line Climbing Flight Aerodynamics of a Fruit Bat" , Physics of Fluids. 2014
© 2012 iScience Times All rights reserved. Do not reproduce without permission.