News

2010 grads take wind energy to battlefield

  • Published
  • By John Van Winkle
  • U.S. Air Force Academy Public Affairs
U.S. AIR FORCE ACADEMY, Colo. --  Alternative energy goes mobile to the battlefield with a research project cadets are working on for the U.S. Army.

Cadets 1st Class John Arvett, Nick Bassett, Robert Hayward and Matt Ludwig, who are electrical engineering majors, teamed with Cadet 1st Class Alex Frank, a mechanical engineering major, and Cadet 1st Class Carrie Moore, a systems engineering major, on the green energy capstone project to design, build and test a Humvee-mounted wind turbine for use in the field.

"Basically, this is a vehicle mounted wind turbine, and the purpose of it is to augment the vehicle's batteries so that when you're running all the communications equipment that's actually in a Humvee, you don't have to idle the engine," Cadet Arvett said. "As it stands now, when the Humvee is parked, and you're running this equipment, you have to idle the engine, which burns fuel. "

This cadet research project, a wind turbine bolted to the Humvee's bumper, aims to stretch the vehicle's fuel capacity.

The six cadets took the idea from theory to a working product over the course of a semester with a budget of $5,000. They made most of the components themselves and even took a few creative design turns along the way, including cannibalizing mountain bike remnants for their battlefield alternative energy project.

"I'm an avid mountain biker, and I've accrued a fair amount of spare parts over the years on a few broken bikes, so I had some old brakes lying around," Cadet Arvett said. "We used the same principle that they use on mountain bikes with the calipers and disc rotor and mounted that to a stationary rotor that is actually on the turbine."

The braking force is about 1,200 pounds, which exceeded expectations and is far more robust than needed -- although this was a requirement never quantified by the user.
"It gives us an ample factor of safety to guarantee that we can stop it in high winds," said Cadet Arvett.

The cadets, who graduate today, successfully tested their lift-based turbine in one of the Department of Aeronautics' wind tunnels. Another group of cadets will continue the project in the Fall 2010 semester. Their next steps will address greater compactibility, durability and gear ratios, Cadet Ludwig said.

"The first step is to add a gear ratio to the turbine for the generators," he said. "You'll increase the torque demands on the turbine, but you'll also increase the (revolutions per minute) range at the generator."

Currently, the wind turbine yields a maximum of about 100 rpms. To increase the output, a 2-1 or 3-1 gear ratio will need to be added to get the turbine up a more robust capacity of 180-200 rpms and greater energy output. After these modifications are in place, cadets will focus on making the turbine easier to break down and better able to handle extreme weather condition ranging from desert to arctic environments, Cadet Ludwig said.

The Green Energy Capstone Team cadets successfully tested the wind turbine and showcased their research at the 2010 Gen. Donald R. Keith Memorial Cadet Capstone Conference April 29 at the U.S. Military Academy. The Air Force Academy cadets' wind turbine design was submitted in the reengineering system track and won first place in competition among Air Force and West Point cadets and students from civilian institutions.

This project may be something the cadets continue when graduate school comes calling. All six of the cadets graduated from the Academy and received their commissions May 26.

"Because the research on this project is so bare bones, there's not very much out there," Cadet Arvett said. "You could write a master's thesis on this."