Numerical Simulation of Water Droplets Falling Near a Wall: Existence of Wall Repulsion

The numerical simulation has been carried out to investigate the motion of a droplet initially near a wall under gravity and confirm the existence of the wall repulsive force on the droplet. The numerical model is developed based on a mass conservation level set algorithm to capture the surface deformation of the droplet. The results show that the wall repulsive force on the droplet initially near the wall plays an important role in the droplet falling process, and the viscosity force affects the oscillatory trajectory of the falling droplet. In addition, the mutual repulsive effect between two droplets is also studied by settling symmetrically two droplets, and the oscillatory mechanism of droplet motion is discussed as well.