MOVEMENT AND SPLASHING OF A DROPLET IMPACTING ON A WET WALL

The liquid layer has an important effect on the movement of a droplet after impacting on a wet wall. The numerical solution of the movement of a droplet impacting on a wet wall was realized by using the combined Level Set-VOF method for gas-liquid interface tracking and the wall wetting model, and the movement of a droplet impacting on a wet wall was researched. The results show that there are several different movement forms after a droplet impacting on a wet wall under different impacting velocities, such as adhesion spreading, wave, crown and splashing, and the pressure distribution induced by the impacting is the main reason of different movement forms. The movement of splashing is a special form of crown movement under certain conditions, and its formation satisfies the theory of capillary breaking. The effect of the impacting velocity on the movement direction of splashing is small, while the effect of the thickness of the liquid layer is bigger. Both impacting velocity and liquid layer have certain influence on the droplet shape, splashing separation position, splashing velocity and splashing occurrence time.