Attenuation effects on imaging diagnostics of hollow-cone sprays.

Detrimental effects to quantitative interpretation of Mie and laser-induced fluorescence images of hollow-cone sprays were investigated. The attenuation of the laser beam leads to locally unknown intensities rendering it impossible to obtain high-fidelity images of these sprays. Two strategies that use bidirectional illumination of the spray are discussed and evaluated. Conditions for which a bidirectional illumination, single-image detection will allow good recovery of the spray structure are identified. Furthermore, the attenuation of laser-induced fluorescence signals on their path through the spray is quantified.