The general dynamic equation for aerosols. Theory and application to aerosol formation and growth

Abstract

Conservation equations for aerosol size distribution dynamics are derived and compared. A new discrete-continuous conservation equation is derived that overcomes the limitations of the purely discrete or continuous equations in simulating aerosol dynamics over a broad particle size spectrum. Several issues related to aerosol formation and growth not previously amenable to exact analysis are studied in detail using the discrete-continuous equation: (1) the establishment of a steady state concentration profile of molecular clusters in the presence of a preexisting aerosol; (2) the relative importance of nucleation, condensation, and scavenging in gas-to-particle conversion; and (3) the importance of cluster-cluster agglomeration relative to other processes. The formation and growth of a sulfuric acid/water aerosol in a smog chamber is simulated using the discrete-continuous equation, and the results are compared with recent experimental data. The above issues related to aerosol formation and growth are investigated for the simulated experiment.

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