- Author
-
Koylu, U.
- Title
- Recent Experimental Studies of Combustion-Generated Nanoparticles. Fire Research Seminar. VHS Video.
- Coporate
- Florida International Univ.
- Report
-
Video
1997
- Keywords
-
combustion
|
light scattering
|
extinction
|
soot
- Abstract
- Nanometer size particles formed from the gas phase process in reaction flows have important environmental and technological implications. For example, the presence of smoke in practical flames dramatically affects the pollution and heat transfer characteristics of many engineering (IC engines) and natural (fires) systems. On the other hand, various types of oxide particles (silica, titania, etc.)( are produced by flame synthesis processes in the pigment industry to be used as reinforcing agents. To reach the ultimate goal of generating particulates with prescribed properties in a specific application, a fundamental understanding of complex processes in particle-laden flames needs to be established based on the data obtained from diverse experimental tools. With this motivation, recent studies of soot formation and alumina synthesis in nonpremixed laminar flames will be presented. The dicussion will include a novel thermophoretic deposition technique which can measure all particle properties (size, morphology, and number density) without a prior knowledge of refractive index and bulk density. The unique abilty of this diagnositc technique to estimate the volume fraction of translucent soot precursor particles will be emphaisized base on implementation within coflow flames. Light scattering measurements for the characterization of oxide particle evolution in a counterflow flame will also be discussed. Additionally, controversies surrounding the spectral extinction coefficient, fractal prefactor, and refractiv index of soot aggregates will be addressed base don theoretical predictions. Fianlly, some research issues that should be investigated in the near future will be highlighted.