Quote:
Originally Posted by bwilson4web
Increasing the air intake charge of a diesel engine, unlike a gas engine, does not increase the power. In fact, it increases the overhead as more work has to be done compressing the larger mass of air.
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Lets get this straightened out right now. Increasing the air intake charge
does create more power for a given quantity of fuel burned.
One very informative paper I keep referencing is
http://aerade.cranfield.ac.uk/ara/1937/naca-tn-619.pdf
in figure 8 they show power output with boost pressure for fixed fuel increments per cycle.
In figure 10 they show what a restriction of air intake does to performance.
in both cases the more in the cylinder results in more power out and higher efficiency for a given quantity of fuel.
If you don't buy that because of the age of the report here is a more modern report abstract
Abstract
"Next, a study of the effects of varying boost pressure levels was conducted. For fixed NOx levels, with low-pressure (90 MPa) single injections, soot was found to reduce monotonically as the boost pressure increased. Interestingly, with low pressure double injections and with high pressure (>90 MPa) single injections, soot was found to decrease at first and then increase as the boost pressure was increased beyond the optimum level. This appears to be due to a reduction in the spray penetration and mixing that occurs as the engine gas density is increased. BSFC also reduced monotonically with increasing boost pressure for all cases. These results suggest that variable geometry turbochargers or other enhanced boosting methods will aid in the reduction of emissions and fuel consumption from heavy-duty truck engines. "
there was a better paper but the link is now dead
http://powerlab.mech.okayama-u.ac.jp...4/A6_1_022.pdf