A Georgia Tech graduate student answered a challenge from NASA in 2014 to design an all-electric aviation vehicle. Tom Neuman, an aerospace engineering student, won top honors in the graduate division of NASA's 2014-15 University Design Challenge with a design for a 3,450-pound, hydrogen cell-powered, four-seat airplane.
The design relies on fuel cells for propulsion and uses an unusual motor placement to maximize efficiency. "For me, working on its design was a window into the possibilities and also a vivid lesson about the significant challenges ahead for electric flight," Neuman wrote in an article for IEEE Spectrum.
Neuman was the only one-person team to take on the NASA challenge, which tasked student engineers to design a four-seat vehicle that could carry at least 400 pounds of extra cargo, fly at least 575 miles during a single flight, cruise at a speed of at least 150 miles-per-hour, and be able to take off in less than 3,000 feet under normal conditions. And it would have to be competitive with standard piston-engine airplanes that burn aviation fuel by 2020.
"The real goal was to be able to travel 1,000 miles at a speed of 190 miles-per-hour, with a payload of 800 pounds. And the game wasn't one of pure number analysis either. They wanted to see a plane that could compete in today's market, with components that are available now to manufacture it."
At an estimated production cost of around $547,500, the Vapor was competitive with the Cirrus SR-22, one of the most popular single-engine gas-powered planes on the market. Not only did it meet the distance and payload demands, Neuman's plane was also shown to be 16 decibels quieter and to consume 3.8 times less fuel than the SR-22.
"We may not have hydrogen refueling stations everywhere yet, but there are economically feasible ways to develop hydrogen on site. It can be derived from natural gas, or biomass," he said.
"And its only emission is water vapor."
Perhaps the most challenging aspect of the design process the development of a validation tool that would benchmark the Vapor's performance. Up until a few years ago, most electric or fuel-cell-powered planes were too small and too slow to meet the NASA specs.
"Given recent advances in fuel cells and electric motors, Vapor, or something like it, could well be built and flown right now. The technology is certainly ripe for exploitation. But it’s unclear how regulatory authorities will react to the advent of such all-electric designs," Neuman wrote.
Neuman describes in detail how he came up with the design in "How I Designed a Practical Electric Plane for NASA..."