Application of a genetic algorithm to the optical characterization of propellent smoke

A search procedure based on a genetic algorithm is used to determine the optical properties and the particle size distribution function of propellant smoke from angular light-scattering measurements. The optical properties and size distribution parameters are obtained by matching theoretical values with measurements of the light scattered by smoke extracted from the plume of propellants that contain aluminum, magnesium, or zirconium carbide. A genetic algorithm is used to find the theoretical scattering pattern that best fits the measured scattering pattern. The measurements presented in this article were not made in situ, and so the results do not accurately reflect the optical properties and size distribution parameters of smoke found in rocket motors and plumes. However, the retrieved optical properties are in agreement with values available in the literature, and the retrieved size distributions are consistent with expectations based on analysis of the sampling method. Therefore, it is clear that the proposed inversion algorithm could be used to determine the optical properties and size distribution parameters from in situ light-scattering measurements if such measurements were available.