Observations of a Correlation Between Primary Particle and Aggregate Size for Soot Particles

Figures & data

FIG. 1. Sample TEM images of aggregates with different primary particle sizes. All scale bars are 100 nm.

TABLE 1 Number of TEM images and particles considered

Source	# Of images produced	# Of aggregates analyzed	# Of primary particles analyzed
GDI engine	670	554	6516
HPDI engine	332	584	4030
Aviation gas turbine	351	292	1279
Inverted burner	144	180	>1608^a

^aThis number corresponds only to the primary particles counted in 89 (of 180) aggregates. Inverted burner samples were analyzed prior to other samples and intermediate image processing results are not available for all equivalence ratios.

FIG. 2. The variation of average primary particle diameter (in individual aggregates) vs. aggregate-projected area equivalent diameter.

FIG. 3. Geometric standard deviation of primary particle in ensembles of aggregates vs. individual aggregates. Each point on this graph corresponds to σ_(g,p,ens) and average σ_(g,p,agg) for an individual operating condition. Solid line shows 1:1 ratio for the x axis and the y axis.

FIG. 4. Effect of shielding on the number of primary particles detectable on projected images.

FIG. 5. Effect of shielding on the average primary particle diameter in individual aggregates detectable on projected images.