Analyzing the Effect of Collision of Droplets on Evaporation Rate

Spray drying is a process used by many industries such as food, agricultural and pharmaceutical to convert a liquid feed into powder. Many studies have used CFD to model fluid and powder flow. However, continuum approaches track bulk powder properties resulting in loss of data for individual particles. To improve the accuracy of these models, fundamental research on drying behavior is critical. This work focuses on simulating the initial phase of the process where an atomized droplet behaves as a liquid due to excess moisture content. At this stage, the droplets collide frequently, and particle size distribution changes rapidly. Accurate calculation of the moisture content of the droplet is essential for further analysis on drying kinetics and morphology of particulate form. A computational framework has been developed where the gas phase is modeled as a continuum and individual droplets are tracked in the Lagrangian frame. Using this approach, individual droplets and their characteristic properties are captured, while evaporation effects are accurately accounted for. This works provides high-fidelity data for particle size distribution and moisture content which paves the path toward modeling of the second phase of drying, when liquid droplet has transformed into a wet-particle.