Characterizing spray pulsations using a phase-Doppler particle analyzer

The present study focuses on understanding the pulsation characteristics of a spray generated with a feed nozzle commonly used in the petrochemical in dustry. A novel technique for characterizing the spray pulsation based on t he data acquired using a phase-Doppler particle analyzer (PDPA) is illustra ted. Two-phase vertical sprays are generated using air and water at three d ifferent air-to-liquid mass ratios. Visual observations using an imaging te chnique indicated the presence of pulsations. Using the PDPA data, an inter mittency factor, gamma, denoting the degree of pulsation is defined. The mo de of injection of the two phases and the effect of the carrier gas on the spray pulsations and the droplet size-velocity characteristics are also inv estigated. The present results indicate that the factor gamma, coupled with the droplet size-velocity distribution, can be effectively used to charact erize pulsating sprays.