Cluster formation by barrier discharge in simulated engine exhaust gas at high temperature

Experiments were performed to examine cluster formation when simulated engi ne exhaust gas passes through an atmospheric pressure plasma discharge cell at 180 degrees C. The gas composition included N-2, NO, CO, CO2, C3H8, C3H 6, Ar, H-2, H2O, O-2 and SO2. Aerosol particles or clusters were measured a fter the gas was treated with a dielectric barrier discharge, although the quantity of clusters generated was several orders of magnitude smaller than normal engine emissions. The clusters were not formed when water was not p resent in the mixture. The number and size of clusters increased when hydro carbons were not present, although the quantity was still very small. Metho ds to describe cluster formation phenomena are discussed. (C) 2000 American Institute of Physics. [S0003-6951(00)00821-4].