Showing papers by "W.P. Jones published in 1992"

Predictions of soot formation in turbulent, non-premixed propane flames

Abstract: Predictions of soot formation in turbulent jet flames have been made by solving the fluid dynamic equations in conjunction with a second-order closure model for the turbulent transport of momentum and scalar fluxes. The gas-phase, non-premixed combustion process is modelled via the conserved scalar/prescribed probability density function (p.d.f.) approach using the laminar flamelet concept. Soot formation, growth and consumption is included through balance equations for soot mass fraction and particle number density which admit finite-rate kinetic effects. Both flamelet and sooting prescriptions are derived from a detailed gas-phase chemistry scheme coupled to a global reaction scheme for soot formation, the latter involving soot nucleation, surface growth, particle coagulation and oxidation steps. Solutions of the complete model are compared with experimental data obtained by Nishida and Mukohara in co-flowing turbulent propane flames. For two air preheat temperatures studied experimentally, predictions of the model are shown to be in good qualitative and quantitative agreement with measured soot concentrations. In particular, the model faithfully reproduces the significant influence of air preheat on the sooting characteristics of the flames.