GELATION AND SELF-PRESERVATION DURING TURBULENCE-INDUCED COAGULATION

Abstract

ABSTRACT Coagulation in turbulent flows is important in natural phenomena like the formation of clouds (Saffman and Turner, 1956) and even protoplanetary disks in solar turbulent nebulas (Sterzik et al., 1995), as well as for industrial processes like the manufacture of carbon blacks, fumed silica and pigmentary titania (Xiong and Pratsinis, 1991). The evolution of the size distribution of aerosols undergoing turbulence-induced coagulation is examined over the full spectrum of particle and eddy sizes. Gelation (Ziff, 1980) and self-preservation (Wang and Friedlander, 1967) behavior is explored for various mechanisms of turbulence-induced coagulation and compared to the corresponding kernel homogeneity. The attainment of asymptotic (or self-preserving) size distributions by coagulation is of particular interest as it simplifies data inversion and facilitates process design through computational fluid and particle dynamics (Johannessen et al., 2001).