Not a fuel substitute but potentially interesting way of reducing the size of an engine to give the same hp output
Taken from the European Automotive design magazine
Ethanol Injections Ramp up Power
MIT researchers are developing a half sized gasoline (petrol) engine that they say performs like its full sized cousin but with the fuel efficiency approaching that of today’s hybrid engine system.
The key technology is a carefully controlled injection of ethanol directly into the engines cylinders when more power and torque is required.
MIT says the engines could be ready for production within 5 years. Customers could then, by spending and extra $1000 or so and adding a couple of gallons of ethanol every few months, have an engine that can go up to 30% further on a gallon of petrol than a conventional engine. Moreover it provides high performance without the use of high-octane fuel.
The researchers believe their ethanol-boosted turbo engine has real potential for widespread adoption. “There’s a tremendous need to find low cost, practical ways to make engines more efficient and clean and to find cost-effective ways to use more bio-fuels in place of oil.” Said Daniel R Chon, senior research scientist in the Laboratory for Energy and the Environment and the Plasma Science and Fusion Centre (PSFC).
For decades, efforts to improve the efficiency of the spark ignition petrol engine have been stymied by “knock” – spontaneous combustion that can cause damage to the engine. Using computer simulation, the MIT team says it has found a way to use ethanol to suppress spontaneous combustion and remove the knock limit.
When the engine is working hard and knock is likely, a small amount of ethanol is directly injected into the hot combustion chamber, where it quickly vaporises, cooling the fuel and air and making spontaneous combustion much less likely. According to MIT, the engine will not knock even when the pressure inside the cylinder is three times higher than that in a conventional engine. Testing by Ford is said to have produced results consistent with simulation model’s predictions.
With knock essentially eliminated, the researchers could incorporate into their engine two operating techniques that help make today’s diesel engines so efficient, but without causing the high emissions of diesels: high levels of turbo charging and a high compression ration.
