Laboratories Looking into New Approach to Car Engines

According to reports, the U.S. Department of Energy’s (DOE) Argonne National Laboratory is collaborating with Delphi Automotive and Achates Power Inc. to develop a state-of-the-art new engine that could yield efficiency gains of up to 50 percent over a comparable traditional engine.

The research is being carried out under a three-year project funded by a $9 million award from DOE’s Advanced Research Projects Agency-Energy (ARPA-E) and an extra $4 million of cost share from the team members.

Combining two promising technologies—opposed pistons and gasoline compression ignition—the new engine is designed to develop a “super engine” that could basically redefine the ay internal combustion engines perform in the light-duty transportation market.

According to Steve Ciatti, who would be the experimental lead for Argonne, traditional spark-ignited engines have enhanced dramatically over the past few years that there is little room to make huge efficiency gains. He said that a game-changer is needed to get into huge double-digit efficiency gains, and they believe this engine is capable of doing that.

The new engine will combine the best characteristics of compression ignition and gasoline engines with a cutting-edge piston architecture refined by Achates Power that sets two pistons moving in opposition in one cylinder. As the pistons’ crowns slide toward each other, they compress a mixture of gasoline and air to such extreme pressures that the mixture auto ignites without spark plugs in a process called compression ignition.

As the pistons reverse course and slide to the opposite ends of the cylinder, ports that are machined into the cylinder enable exhaust gases to escape while fresh air is taken in, then the pistons move together again to compress and ignite in a two-stroke cycle. This design eliminates cylinder heads—which are found as the leading cause of inefficiency and heat loss in traditional engines—and enables the engine to run with diesel-like power and efficiency, while maintaining the emissions benefits of gasoline.

Achates Power conducted an analysis, which showed that the new engine will yield fuel efficiency gains of over 50 percent compared with a downsized, turbocharged, direct-injection gasoline engine, while reducing the cost of the powertrain system.

The development of such a new engine will call for the know-how of all the team members, who bring together years of experience in different aspects of engine design and production.

In a statement, Doug Longman, who will be the project manager for Argonne, said that the dynamics of this team are perfect to make the project work. He noted that the combination of Argonne’s scientific and engineering experience with Achates Power’s engine architecture and Delphi’s expertise in fuel injection and gasoline direct-injection compression ignition will provide them with the tools to develop an engine they think is going to show extremely huge efficiency gains.

The modeling and simulation of the complex fluid dynamics and combustion inside the engine—which will be carried out through Argonne’s Virtual Engine Research Institute and Fuels Initiative (VERIFI)—is also considered a contributor to the project’s success. By utilizing high-performance computing to the model and forecasting the movement of air and fuel in the cylinders, the VERIFI team will be able to enhance the design of both the engine and fuel injectors.

According to Sibendu Som, Argonne’s computational lead for the project, modeling and simulation have become ever more critical to engine designers in recent years. He claimed that using VERIFI to enhance combustion technologies for the industry has considerably shortened development times and helped lead to more efficient engines.

Shorter development time, thanks to computational modeling and efficiency gains that are developed through experimental research will be crucial to the development of an engine that can be widely embraced commercially. Over the years, companies have proposed a number of engines that show benefits over traditional spark-ignited gasoline engines, but the efficiency gains have not been dramatic enough to convince automakers to retool production lines and car designs to integrate the new approaches. This new research team is slated to break that barrier and develop an engine that could revolutionize the automotive market.