Droplet Motion and Phase Change Model with Two-Way Coupling

The droplet interacts intensively with surrounding gas when moving and evaporating in the gas, of which the mutual effects of the gas and the evaporating droplet need to be taken into account. For the typical droplet model, the gas parameters are usually considered as that at infinity and the local parameter variation surrounding the droplet is neglected, consequently leading to some discrepancies. This research tries to develop a new moving droplet phase change model with two-phase coupling which characterizes the local parameter variation of gas phase surrounding the evaporating droplet. Firstly, the interaction mechanism of two phases is presented based on the droplet evaporation phenomena. Then, the droplet motion and phase change model is developed through the theoretical derivation. Subsequently, the analysis of the evaporation characteristics of the injected droplets in the hot air is conducted to simulate the operation process of the containment spray system in the nuclear power station. The numerical simulation indicates the refined droplet model is more capable for precise prediction of the situations with large quantities of evaporating droplets and with intensive interactions between two phases.