Prediction of Droplet Size and Velocity Distribution in Spray Using Maximum Entropy Method

The distribution of sizes and velocities of droplets initially formed in sprays is an important piece of information needed in the spray modeling, because it defines the initial condition of the spray droplets in the predictive calculations of the downstream flow fields. The early stage of the atomization process (Primary Breakup) is clearly deterministic, whereas the droplet formation stage is random and stochastic. The stochastic aspect deals with the stage of droplet formation after the liquid bulk breakup by statistical means through the maximum entropy principle (MEP) based. The MEP provided model predicts atomization process while satisfying constrain equations of mass, momentum and energy. This model is capable for considering drag force on droplets downstream through a gas field. The model prediction is compared favorably with the experimentally measured size and velocity distribution for droplets, near the liquid bulk breakup region, produced by an air-blast annular nozzle. Therefore, the present model can be used to predict the initial droplet size and velocity distribution in droplet formation region of sprays.