Simulation of liquid spraying in the dripping mode by using the level set method

Injection of a liquid into another immiscible liquid and its breakup and formation of droplets has a basic importance in many industrial processes such as liquid-liquid extraction. In this study, liquid spraying process and drop formation in the dripping mode is simulated using a sharp interface method and effect of important parameters on this process such as Weber number, Ohnesorge number and Bond number is investigated. The level set method is used for interface tracking. Some quantities such as pressure and fluid properties are discontinuous across interface. In this research, discontinuities at the interface are imposed using the ghost fluid method. It is observed that by increasing Weber number (from 0.0027 to 0.1875), the length of the outlet liquid is increased about 7 percent and the liquid breakup time is decreased about 52 percent. Also, at higher Weber numbers, the liquid return toward nozzle after droplet detachment is less. Increasing Ohnesorge number (from 0.0002 to 0.189) increases the length of the outlet liquid about 21 percent and breakup time about 151 percent. Also, at higher Ohnesorge numbers, the liquid return toward nozzle is higher. Increasing Bond number (from 7 to 39) leads to the reduction of the length of the outlet liquid and breakup time about 26 and 91 percent, respectively. Also, at higher Bond numbers, the liquid return toward nozzle is less. Another considerable result is the reduction of the size of formed droplets by enhancement of Bond number.