01-30-2008, 04:54 AM
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#2 (permalink)
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Pokémoderator
Join Date: Dec 2007
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Hello -
This is beyond our capabilities, but here's a little more from the same professor dude :
Offroad Exhaust
http://www.motorhelmets.com/htm1/bod...le-offroad.htm
Quote:
Researchers at Kettering University are trying a novel approach to increase the efficiency of diesel engines. By recirculating exhaust gas to the cylinder, they will not only cut down on NOx formation, but if they can keep the exhaust gas from mixing with air, they hope also to reduce pumping losses.
They are looking at a two-zone combustion system in which air is held in the center of the cylinder and is surrounded by recirculated exhaust gases, which are all but void of oxygen. An intake system that can control the balance between the air and exhaust controls the amount of oxygen in the cylinder, and can replace a throttle.
During intake, the piston's work to reach the end of its stroke increases with the throttling of the airstream. As intake is restricted, resistance to the stroke increases. The pumping takes some of the engine's power.
If throttling results from the balance of the gases, however, their total volume remains consistent,and the engine avoids pumping losses. Fuel economy could improve significantly, according to Bassem Ramadan,
an associate professor of mechanical engineering who heads the project at the university in Flint, Mich.
The key is in keeping the gases separate.
"Some results look promising, but further work is needed to determine if the two regions will remain unmixed during the engine operating cycle," he said. While complete stratification would be ideal, he expects that maintaining partial stratification of about 80 percent during the compression stroke is acceptable.
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CarloSW2
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