Estimation of the Fractal Dimension of Diesel-Combustion Generated Nanoparticles

The fractal nature of diesel exhaust aggregates has profound implications on their transport and thermal properties. However, the measurement of the fractal dimension requires sophisticated techniques (see, e.g., Van Gulijk C. et al. (2004) that are not easily available. We propose an algorithm for the self-consistent determination of the average fractal dimension of non-volatile solid particles emitted by light-duty diesel vehicles (Isella et al., 2008). Experimental number distributions are taken from vehicle emission measurements performed at the VELA-2 laboratories of the Joint Research Centre. Measurements at the inlet and outlet of the transfer tube that conducts exhaust fumes from the vehicle tailpipe to the dilution tunnel are analyzed. Agglomeration, diffusional and thermophoretic transport are considered to be the main aerosol dynamical processes. The experimental procedure was chosen to minimize gas-to-particle conversion processes. The proposed algorithm is similar to procedure used by Maricq (2007), but it differs in that it relies on mass than on number distributions.

ISELLA Lorenzo;  GIECHASKIEL Barouch;  DROSSINOS Ioannis; 

2009-02-03

Hellenic Association for Aerosol Research

JRC49183

http://www.eac2008.org/EAC2008-Program.htm,    https://publications.jrc.ec.europa.eu/repository/handle/JRC49183,