It is the use of a lean fuel mixture
in the HCCI engine that prevents the autoignition of the fuel from damaging the engine.
It uses a catalytic combustor to burn a lean fuel mixture
at a temperature below that at which nitrogen oxides, a component of pollution, are produced.
Because we can predict when we are going to have to start the engine," says Louckes, "this allows us to preheat the catalyst, warm the combustion chamber, and run the engine on a lean fuel mixture
, which drastically reduces emissions and oil contamination," says Louckes.
What's more, lean fuel mixtures
and alternative fuels are more difficult to ignite.
The lean fuel mixtures
, studied in a cylinder roughly 30 centimeters in diameter, generated unusually cool flames with about one-hundredth the power of a common match flame, says project scientist Karen J.