Browse Publications Technical Papers 2019-01-0019

Optical Diagnostics of Spray Characteristics and Soot Volume Fractions of n-Butanol, n-Octanol, Diesel, and Hydrotreated Vegetable Oil Blends in a Constant Volume Combustion Chamber 2019-01-0019

The effects of using n-butanol, n-octanol, fossil Diesel, hydrotreated vegetable oil (HVO), and blends of these fuels on spray penetration, flame and soot characteristics were investigated in a high-pressure high-temperature constant volume combustion chamber designed to mimic a heavy duty Diesel engine. Backlight illumination was used to capture liquid and vapor phase spray images with a high-speed camera. The flame lift-off length (LOL) and ignition delay were determined by analyzing OH* chemiluminescence images. Laser extinction diagnostics were used to measure the spatially and temporally resolved soot volume fraction. The spray experiments were performed by injecting fuels under non-combusting (623 K) and combusting (823 K) conditions at a fixed ambient air density of 26 kg/m3. A Scania 0.19 mm single straight hole injector and Scania XPI common rail fuel supply system were used to produce injection pressures of 120 MPa and 180 MPa. To evaluate the effect of cetane number (CN) variation on combustion processes and soot emissions, di-tertiary-butyl peroxide (DTBP) was added to one blend to modify its CN without greatly altering its composition. The different fuels exhibited similar vapor phase penetration, but their liquid phase penetration varied significantly with the fuels’ physical properties. HVO exhibited the longest steady state liquid penetration. A fuel has a longer ignition delay, resulting in a longer flame lift-off length and thus a lower soot optical thickness and soot volume fraction distribution. Compared to Diesel fuel, n-butanol blends and n-octanol produced much lower soot emissions because of their oxygen content, lower stoichiometric A/F ratio, and high latent heat of vaporization.


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:

Effects of Aromatics Content and 90% Distillation Temperature of Diesel Fuels on Flame Temperature and Soot Formation


View Details


A Comparison of Combustion and Emissions of Diesel Fuels and Oxygenated Fuels in a Modern DI Diesel Engine


View Details


Impact of Fuel Properties on Diesel Low Temperature Combustion


View Details