Browse Publications Technical Papers 2002-01-0889

Effects of Fuel Parameters and Diffusion Flame Lift-Off on Soot Formation in a Heavy-Duty DI Diesel Engine 2002-01-0889

To better understand the factors affecting soot formation in diesel engines, in-cylinder soot and diffusion flame lift-off were measured in a heavy-duty, direct-injection diesel engine. Measurements were obtained at two operating conditions using two commercial diesel fuels and a range of oxygenated paraffinic fuel blends. A line-of-sight laser extinction diagnostic was improved and employed to measure the relative soot concentration within the jet (“jet-soot”) and the rates of soot-wall deposition on the piston bowl-rim. An OH chemiluminescence imaging technique was developed to determine the location of the diffusion flame and to measure the lift-off lengths of the diffusion flame to estimate the amount of oxygen entrainment in the diesel jets.
Both the jet-soot and the rate of soot-wall deposition were found to decrease with increasing fuel oxygen-to-carbon ratio (O/C) over a wide range of O/C. Good agreement between soot-wall deposition and jet-soot measurements indicates that using the soot-wall deposition diagnostic to indirectly measure jet-soot is valid. This is especially useful when the jet-soot is too optically thick to be measured directly. OH chemiluminescence imaging indicated little differences in the flame lift-off and corresponding oxygen entrainment between fuels. Commercial diesel fuels displayed higher sooting tendencies than the zero-oxygen-content paraffinic fuel blend. Since the estimated oxygen entrainment rates were similar, differences in soot formation are most likely due to the effects of fuel chemical structure. A linear extrapolation of the soot-wall deposition data for the oxygenated, paraffinic fuels predicts that zero soot formation may be achieved when the fuel atomic O/C exceeds 0.4.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Heavy-Duty Diesel Emissions from Operation on Crude and Minimally-Processed Shale Oils


View Details


The Potential of Using Vegetable Oil Fuels and Ethanol as Fuels for Engine Operation at Heights Well Above Sea Level


View Details


Comprehensive Characterization of Particulate Emissions from Advanced Diesel Combustion


View Details