2007 Volume 86 Issue 3 Pages 186-192
Spectroscopic study on local radiative properties of luminous flame, i.e. emission from soot could, with various hydrocarbon fuels (methane, ethane, propane, butane) are performed by utilizing 1-D counterflow burner. Emission from soot from counterflow diffusion flames is analyzed and bulk emissivities of soot cloud by different kind of fuels are obtained. Model parameter of emissivity, α(εLF=εLF(λ-α)): wavelength dependency to the bulk emissivity, is calculated in different locations. Various fuel types and imposed flow velocities are considered as experimental parameters in the present study. As the carbon number of the fuel is increased, the produced soot cloud tends to be optically thick and the wavelength dependency parameter, α, becomes smaller. This trend suggests that the luminous flames provided by high-carbon contained fuel is close to gray-body emitter. An engineering model parameter, ξ, is introduced for precise prediction of the universal local soot condition and it works fairly well in the wide range of the fuel (C1∼C4) under the conditions considered in the present study.
