A comprehensive model on spray formation process and probability distribution of subsequently formed spray droplets

Spray combustion remains the dominant mode of energy conversion, providing the majority of the world´s energy requirement. A good understanding of spray formation process and spray droplet size distribution is essential for the design and operation of spray combustion systems with high energy efficiency and low pollutant emission. The early stage of spray formation process is clearly deterministic with distinct unstable wave motion, whereas the final stage of spray formation process is more or less random, chaotic and stochastic due to nonlinear effects of the unstable wave development. The number of droplets produced in a spray is enormous, and description of each individual droplets becomes highly improbable, thus requiring statistical treatment. The present model incorporates the deterministic aspect by linear and nonlinear stability theory, and a stochastic aspect by the statistical means through the maximum entropy principle, and it can predict, from a given flow condition at the nozzle exit, the spray formation process and the probability distribution of subsequently formed droplets in sprays. The effect of flow conditions at the nozzle exit on the droplet size distributions has been investigated. The present predictive model gives the initial distribution of droplet diameter and velocity in sprays, and hence will be useful as a submodel for overall spray combustion modelling