The heavy, bulky insides of what’s beneath vehicle hoods could be a thing of the past, based on new research at Michigan State University.
Cooking-pot-sized generators could replace most of what’s under the hood in hybrid cars, which would mean lighter, cheaper, cleaner and more efficient vehicles.
MSU engineers are developing such a device — called the Wave Disk Generator — made of curved blades on a spinning disk. Air and fuel are pumped into the channels between the blades and pressure builds up, causing a shock wave. When compressed, the air and fuel ignite. After combustion, the high-speed gases are released through exhaust ports, causing the disk to spin and generate electricity.
The small engine replaces traditionally used pistons, camshafts and valves.
“The main difference between this and the automobile engine in your car is that the piston is fixed in your car,” said Indrek Wichman, MSU professor of mechanical engineering and researcher on the project. In the Wave Disk Generator, “the combustion that takes place moves around in a circle.”
Wichman said the generator could be used on hybrid cars to charge the battery, eliminating the need for a cooling system and several other parts. Most hybrid cars store energy in batteries for their electric motors.
Researchers estimate the generator could replace approximately 1,000 pounds of engine, transmission, cooling system and fluids, making hybrid vehicles about 30 percent lighter and 30 percent less expensive. The generator is also estimated to cut carbon dioxide emissions by 90 percent from regular cars with internal combustion engines.
Several prototypes have been built and automotive manufacturers have expressed interest in the technology, said Tonghun Lee, professor of mechanical engineering at MSU and researcher on the project.
Norbert Müller, associate professor of mechanical engineering at MSU, leads the Wave Disk Generator project.
The Advanced Research Project Agency—Energy, which invests in high-risk, high-reward energy projects, kick-started the wave disk research at MSU with $2.5 million in January 2010. The agency says about 85 percent of car fuels, in traditional engines, is lost as what is called waste heat, and only 15 percent to 20 percent is turned into motion. The Wave Disk Generator is estimated to use 60 percent of fuel for propulsion — or actually making the car go — cutting wasted fuel in half.
The versatile generators can be used in motorized scooters, large trucks and everything in between, so long as it’s a hybrid.
“The generator can charge a battery to run a hybrid, but it won’t work like a regular car engine,” Wichman said.
But Wichman thinks the generator could move beyond just hybrid cars, to be used whenever there’s a need to produce power.
“This kind of engine could be used for a house … a manufacturing plant. … I’m not so sure it will only be put under car hoods,” Wichman said.
There were skeptics at first, but the project has continued to prove them wrong, said Pablo Parraga, a doctoral student at MSU and research assistant on the project.
“We have proven the concept,” Parraga said. “We have moved past the challenges and now things are really working.”
Parraga said a major concern was igniting a mix at such high speeds.
“This is an area that didn’t have much research, and we’ve proved with the higher speed combustion, that, yes, we can do it,” Parraga said.
Funding for the project, which started more than two years ago, is winding down. Researchers are looking for more money to keep going and commercialize the Wave Disk Generator. The feds aren’t ruling out continued support.
“We do have the option to extend programs, but initially projects and programs are set up for three years,” said Peder Maarbjerg, assistant director for external coordination at the Advanced Research Project Agency–Energy.
“Someone could certainly do a part two if we see there’s a need to advance the technology,” Maarbjerg said.
Maarbjerg said his agency looks to fund projects that would “put old technologies out of business,” but couldn’t comment on future funding for the wave disk project.