Meaner, greener fuel injection project

Researchers at Wright State University are working on a direct fuel injection project for gasoline engines that burns fuel more efficiently while providing more power and benefiting the environment by reducing pollution through cleaner emissions.

Haibo Dong, an assistant professor of mechanical and materials engineering, is the principal investigator on a $31,000 grant from the Dayton Area Graduate Studies Institute to apply direct fuel injection to small unmanned aircraft vehicles (UAVs) used by the Air Force. The project also has positive implications for the auto industry.

“Many of the UAVs used by the Air Force use small commercial gasoline-powered engines that require high-octane fuel. Operating UAVs on high-octane gasoline presents several operational and logistical problems for the Air Force. The low-octane JP8 is prevalent on most every Air Force base, while high-octane gasoline may be more difficult to acquire, especially in remote locations. Storing and transporting the high-octane gasoline can also cause problems. Direct fuel injection systems operate on low-octane fuel, which could save money in fuel costs while also providing a higher-power output.” He said use of low-octane fuel could eventually meet an Air Force goal of one common fuel for all aircraft and thus be a significant cost savings.

Dong said that by using a fine, ready-to-explode mist, direct fuel injection breaks the gasoline into smaller droplets, which results in more complete combustion from each drop of gasoline. This technology allows spark ignition engines to burn regular or alternative fuel more efficiently, thus resulting in cleaner emissions and increased fuel economy.

He said direct fuel injection differs from the traditional indirect fuel injection now common in most autos. In a traditional fuel injection system, the gasoline and air are pre-mixed just outside the cylinder at the intake manifold. In direct injection, the air and gasoline are not pre-mixed; air comes in via the intake manifold while the gasoline is injected directly into the cylinder.

Although his current grant pertains to UAVs, Dong said the research has positive implications for the automobile industry by helping address President Obama’s desire to make American cars nearly 40 percent more fuel efficient by 2016. “Most fuel injection autos on the market today use the indirect system,” he explained, “and the direct fuel injection means a lower-octane gasoline, which is cheaper and also more fuel efficient.”

Dong has been researching direct fuel injection for the past two years, and during this time he has received more than $200,000 in research grants.