This story ran 1/9/2012 for the UW-Madison College of Engineering

For the past several decades, engineers have been investigating low-temperature combustion as a means of creating engines with diesel-like efficiency and no pollutant emissions.

Optimizing low-temperature combustion to produce the most efficient possible engine also means considering lots of variables. In fact, the very nature of low-temperature combustion involves a reaction with little active control: You inject the fuels, mixing occurs, and then some time later, combustion starts. “We’re always on the edge of doing something bad,” says David Rothamer, an assistant professor of mechanical engineering at the University of Wisconsin-Madison.

That “something bad” could result in the engine not starting, running at too high of a temperature (which produces toxic nitric oxide) or too high of a fuel-to-oxygen ratio (which produces soot). “Lots of times we don’t know where we are relative to those bounds,” Rothamer says. “We need to be perfect within a small range.”

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