By Jon Harper, National Defense Magazine
/ Published August 14, 2015
The Air Force is hoping that a prize contest will yield a revolutionary new engine that doubles the fuel efficiency of current systems.
The $2 million Air Force prize will go to the first team that is able to build a new turbine engine that meets the service’s specifications, said Air Force Lt. Col. Aaron Tucker, program manager of the prize.
“We want to energize research into topics that support the Air Force mission, and turbine engines provide power in a lightweight, low profile package for airborne systems,” he said at an Association of Unmanned Vehicle Systems International conference in Atlanta in May. “A prize excites and motivates talented people.”
The new engine must be big enough to power a medium-sized drone but more cost-effective than larger power plants, he said. A full list of criteria can be found on the contest website at www.airforceprize.com.
Registration opened in May. As of press time, none of the participants’ engines had reached the verification testing stage, which is slated to take place at Wright-Patterson Air Force Base, Ohio.
Tucker said $2 million is the largest monetary prize ever offered by one of the military services. The contest was inspired in part by the Defense Advanced Research Projects Agency’s robotics competition, which used prize money to motivate civilian engineering teams to build cutting edge robots that could perform disaster response missions.
New 21 C via youtubeA robot opens a door during the 2015 DARPA robotics competition.
The engine contest is being administered by the Air Force Research Laboratory, which has a mission of developing technologies to boost U.S. airpower.
The AFRL has laid out challenging criteria for participants. The turbine engine must be in the 100 horsepower class, with a 2.0 brake-horsepower per pound (bhp/lb) or better power to weight ratio. It is also required to have a brake-horsepower specific fuel consumption of 0.55 pounds per brake-horsepower per hour (lb/bhp/hr) or less at maximum continuous power. Those standards would double the fuel efficiency of existing turbine engines of that class. The new engine would weigh a fraction of piston engines in the 100 horsepower class and have 10 times the life span, according to the Air Force.
“With this prize they’re trying to get inventors to develop a turbine engine that has the power density of a turbine and good power to weight [ratio] and … also has the specific fuel consumption of a piston engine. So in a sense they want a jet engine that gets better gas mileage,” said Mike Heil, president and CEO of the Ohio Aerospace Institute and former director of the Air Force Research Laboratory’s propulsion directorate.
The AFRL wants the best of both engine worlds. William LaPlante, assistant secretary of the Air Force for acquisition, said the service wants to hit the “sweet spot” between the capabilities of turbine and piston engines. “It’s something that doesn’t exist right now, this class of engine,” he said in July at the Center for Strategic and International Studies, a Washington, D.C.-based think tank.
FAA handbook via Wikimedia CommonsDiagram of a typical gas turbine jet engine. Air is compressed by the fan blades as it enters the engine, and it is mixed and burned with fuel in the combustion section. The hot exhaust gases provide forward thrust and turn the turbines which drive the compressor fan blades.
Jets can generate more power than piston engines, but they are less fuel efficient. “That’s why you don’t see many turbine-powered automobiles because their gas mileage would not be very good,” Heil said.
A key requirement for the new engine is that it must run on standard Jet A fuel.
“The other problem with piston engines is they require gasoline. … The Air Force and the military want to only deal with only one fuel when they’re deployed and operating — and that is Jet A jet fuel. So they want to get away from having to carry a secondary fuel with them,” Heil explained.
Tucker noted that relying on aviation gasoline in addition to jet fuel is “one of the major drivers of the specific logistical [tail] in combat operations, and we’d really like to remove that requirement.”
To succeed, engineers must improve performance when it comes to SWAP — size, weight and power. The Air Force is trying to reduce the weight and size of remotely piloted aircraft propulsion systems while maintaining the same power and reducing fuel consumption. Such a system would offer key advantages over the piston engines used by medium-sized drones like the MQ-1 Predator, aviation experts said.
U.S. Air Force photo/Lt Col Leslie PrattThe MQ-1
“The turbine engines tend to have longer lifetimes and require less maintenance, so they’re trying to achieve some logistics advantages as well,” Heil said. “By going to a lighter, more compact engine with the same horsepower [and] with better fuel consumption, they will get more range and they will get more endurance. So there will be operational benefits through this improvement as well.”
Tucker said a lighter weight engine and decreased fuel fraction would enable UAVs to carry a heavier payload on their missions.
Whether any of the participants can pull off the design and engineering feat remains to be seen. Experts said meeting the contest’s technical requirements will be challenging.
“I haven’t seen anything quite as ambitious as that as far as the percentage of improvements go,” said Bill Storey, president of the Teal Group, a Virginia-based aerospace and defense market analysis firm. “I don’t quite know how they can do it. Usually the design goals are to reduce fuel consumption by 15 percent or increase durability and that sort of thing. That’s generally an evolutionary development in gas turbine engines rather than revolutionary.”
Tucker said recent advances in composite materials and manufacturing technologies, such as 3D printing, could facilitate development efforts and give smaller companies precision machining capabilities that were previously only available to larger firms.
Using a contest to spur R&D for ambitious engine advancement makes sense for the military, Storey said.
“It sounds like the Air Force is just sort of challenging industry to see what they would come up with and have a safe route to experiment with evolutionary technologies on the smaller end of things rather than incorporating it into a new fighter engine or something that would be very risky,” he said. “It’s less risk and less cost to play with new technology on a smaller program like this [which is] something that might bear fruit for the major programs down the line."
Krystal Ardrey/U.S. Air Force via APAn F-16 engages its afterburner while leaving Incirlik Air Base in Turkey.
Congress authorized the Pentagon to award prizes as an acquisition model in the fiscal year 2013 National Defense Authorization Act. Earlier this year, Air Force Secretary Deborah Lee James picked the turbine engine to be the focus of the service’s first contest. “To me that shows the importance of propulsion and particularly propulsion for UAVs. So that shows that it’s a high priority for the Air Force and the Department of Defense,” Heil said.
However, the relatively small financial reward — when compared to the payoff for programs of record — may not be enough of an incentive to attract larger defense contractors. “As far as the jet engine business goes within DoD, this is pretty small potatoes,” Storey noted.
A spokesman for Pratt & Whitney said the company has no plans to participate in the contest because the award value is so low. As of press time, all of the registered participants were small companies, venture capitalists or individuals with engineering backgrounds.
One such company is Volta Volaré, an Oregon-based aviation company. It found out about the Air Force Prize contest from a Twitter feed. Volta Volaré had not previously done any work for the U.S. military.
“This would be our first foray. And we’re so excited about it. It’s right up our alley … and I was so pleasantly surprised when we saw this opportunity come about,” said president and CEO Paul Peterson.
The company is tweaking the design of one of its existing engines and is optimistic that it will meet all of the prize criteria, he said.
Andy Morris via YoutubeA jet enginge test.
“I hope that we’ll be able to make a better product and serve the warfighters,” he told National Defense.
Tucker said he understands that a $2 million prize might not even be enough to fully finance a team through the entire development process. But he’s hoping that the prestige factor and the potential opportunity to sell the engine in the civilian market will draw participants.
“We expect some motivation to be the cache associated with receiving the first Air Force Prize,” he said.
Winning the contest does not guarantee that the Air Force will buy the contestant’s turbine engine, Tucker noted. Participants own their engine and the rights to the design and intellectual property. The Air Force will own the data from the verification testing, but the contestants will have a perpetual, royalty free, non-exclusive license to use the test data for any purpose.
Although there is no current program of record for which the service is developing the engine, Tucker said the contest “will educate our judgment on the system and its technological approach for the development of a typical research-and-development contract as appropriate.”
“We see it as an important part of our turbine engine portfolio,” he added. “We’re always interested in innovative technology with direct impact. And there are other acquisition methods by which to acquire these beyond this Air Force prize.”
Despite the relatively low prize payout, experts see business opportunities for a company that is able to win the contest and mass produce its engine.
Northrop GrummanThe Global Hawk UAV.
“Your larger UAVs like the Global Hawk, they already have a jet engine on them,” Heil said. “What they’re doing is they’re talking about the smaller class of UAV — Predator class and smaller — of being able to convert them from a piston engine … to a turbine engine. … So I think it would open up all those classes of smaller UAVs that the Air Force and the other services would be interested in operating.”
A next-generation turbine engine could potentially be used on a variety of platforms, not just drones. Air Force officials said they would be interested in using it to power small manned aircraft, cruise missiles and fixed power plants.
Tucker said soldiers could potentially use the engine to power all-terrain vehicles, vertical lift aircraft and generators when they are operating “off the grid” in austere environments.
“If this works … it has huge applications,” LaPlante said, noting that it could result in technology spillover to the civilian market for use on airplanes, ATVs, watercraft and other machines.
Heil said the engine could also potentially be adopted for commercial UAVs, which are proliferating rapidly.
“There are challenges,” he noted. “You’ve got to manage the noise and the vibration and the exhaust and all those kind of things. But I think if they’re successful with this prize and if an engine gets developed that is applicable for these unmanned aerial vehicle applications, there could be other markets in other areas for it.”
Storey said the engine would have to be cost competitive with existing technologies in order to penetrate the civilian market. “There are a lot of small engines out there, and a revolutionary design could certainly make some inroads into these applications,” he said.
Heil said the contest is a good way to get non-traditional players involved in advancing Air Force technology. But a small group that builds the winning engine would face choices about how to bring it to market.
Kevork Djansezian/Getty ImagesMaybe Elon Musk and Spacex would like to throw their hats in the ring?
“They may want to team with one of the bigger companies in doing this. But I suspect a lot of them will be off doing it on their own now,” he said. “If it’s a winning design with market potential, of course they will be of interest to the big companies that are in the business of building turbines. But who’s to say they won’t be like a SpaceX or some of these other companies that will go ahead and strike it out on their own and get some venture capital and start a whole new company?”