The aerodynamic diameter and specific surface area of branched chain-like aggregates

The thesis deals with the microscopic aerodynamic characterization of the branched chainlike aggregates frequently found in polluted air and produced by such mechanisms as combustion of hydrocarbon fuels and condensation of metallic vapors. The dependence of the aerodynamic behavior and specific surface area of such aggregates on their microstructure is evaluated experimentally by the exploding-wire method for iron oxide, gold, and copper oxide aggregates as well as for fluorescein aerosol. The motion of small particles in a gas is analyzed, paying special attention to the influence of viscous slip. Calibration of a Stoeber aerosol centrifuge is discussed, a relation between aerodynamic diameter and particle deposition location is obtained from the calibration experiments, and data needed for a proper measurement of the aerodynamic diameter distribution are evaluated. Results are presented for an experimental study of aggregate aerodynamic characteristics, and results obtained for the specific surface area of iron oxide aggregates are reported.