AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Equivalent-Diameter Relationships for Cluster-dense Soot in the Continuum Regime
Saif Kazi, PAI LIU, Ian Arnold, Rajan Chakrabarty, Washington University in St. Louis
Abstract Number: 697 Working Group: Aerosol Physics
Abstract Past studies showed that a negative gravity (-g) co-flow diffusion flame forms cluster-dense soot super aggregates (SAs) with their physical size reaching the sub-millimeter scale. However the corresponding aerodynamic size of these particles could be significantly smaller owing to the porous nature of gel materials. In this study, experiments were conducted to determine the relationships between aerodynamic radius (Ra), radius of gyration (Rg), and projected area equivalent radius (Rp) of soot SAs produced using a –g ethylene flame. The Ra was estimated from the gravitational settling behavior of SAs in stagnant air, while Rg and Rp were measured using image analysis of optical micrographs. Results showed that for cluster-dense soot SAs, Ra was approximately one order of magnitude smaller than Rg and Rm. Empirical equations between the three equivalent sizes in the continuum regime have been formulated.