The Coagulation of Soot Particles with van der Waals Forces

A detailed calculation of the coagulation kinetics of a soot aerosol has been performed by simulating numerically the coagulation kinetics with the inclusion of van der Waals forces. The van der Waals forces between two soot particles at 1600 K and 1 atmosphere give rise 10 a collision rate enhancement which varies between a maximum of about 2.4 for 1 nm diameter particles to just over 1 for particles of dissimilar sizes. The total coagulation rate with the estimated enhancement factors was about twice the unenhanced rates; this compares favorably with experiment. Over the duration of the computation the soot aerosol size distribution approaches closely the self-preserving form, whether or not the collisional enhancement factors are included.

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