Influence of ash-soot interactions on the reactivity of soot from a gasoline direct injection engine

Figures & data

Table 1. Fuel injection and pressure set points.

Operating condition	Fuel injection pressure	Fuel injection timing (before top dead center of the combustion event)
Baseline	6 MPa		287°
Late start of injection	6 MPa		150°
Early start of injection	6 MPa		325°
Low injection pressure	2 MPa		287°

Figure 1. T10-90 times for soot from the various engine operating conditions.

Figure 2. Comparison of TGA data from iso-thermal oxidation at 500 °C.

Figure 3. Soot oxidation time, T10-T90, plotted against engine-out soot levels and approximated ash fraction.

Figure 4. STEM + EDS results baseline: (a) dark field image, (b) EDS spectra.

Figure 5. A_D1/A_G and I_D1/I_G ratio for the four operating conditions.

Figure 6. Atomic percentage of various bonding states for both oxygen and carbon.

Figure 7. TEM images of the soot oxidation process: (a) baseline 0% – 300k, (b) early SOI 0% – 200k, (c) baseline 40% – 160k, (d) early SOI 40% – 160k, (e) baseline 75% – 160k, (f) early SOI 75% – 160k.

Figure 8. STEM + EDS results, baseline – 75% oxidized: (a) dark field image, (b) EDS spectra.

Figure 9. Phases of soot oxidation.