The objectives of this project are to experimentally examine the effects of radiative heat transfer on the coagulation rates of soot particles formed in hydrocarbon flames. Recent theoretical studies micrometer sized, carbonaceous soot particles in high-temperature gases, indicated that particles cooler than the gas can have diffusion and coagulation rates one order of magnitude greater than those predicted from conventional Brownian dynamics. A net radiative absorption by the particle, on the other hand, can act to decrease or freeze the coagulation rate. In the proposed work, the theoretical predictions will be directly examined through measurement of the size, number density, and coagulation rate of soot particles. Particle measurements will be performed using non- intrusive laser light extinction and scattering methods. Demonstration of a relationship between radiation and soot particle dynamics would provide valuable insight into the factors affecting combustion particulate transport and growth, and would have important consequences on the scaling of particle dynamical models from small to large scale combustion, environments. In addition, the results will e used for the development of new methods of particulate control and removal from combustion exhaust gases. //
