Monochromatic Absorption of Luminous Flames

A spectral absorption coefficient for soot in the visible range, whose first approximation given by is proposed in terras of the Penndorf expansion of the Lorenz-Mie theory. Here λ, m and D are the wavelength of radiation, the complex refractive index and the diameter of particles, respectively. The study provides a fundamental base for the experimental data hitherto correlated by the empirical relation Kaλ ∼ λ−1.39.