Numerical Study of Droplet Behavior in Straight and L-Shaped Channels

Abstract

Numerical simulations using three-dimensional front tracking method are conducted to study the effects of droplet properties on the transient motion, rotation and deformation of a droplet during its transit in straight and L-shaped rectangular channels. The properties under investigation for straight channel are the density ratio, viscosity ratio, Reynolds number, Weber number and droplet initial position. The latter two parameters are chosen for the study of L-shaped channel. The results show that in the straight channel, despite the droplet initial positions, the droplet with the same properties ends up at the same equilibrium position. However, when the Reynolds number increases, the droplet is heavier or less viscous or droplet becomes more deformable, the droplet equilibrium position is much closer to the wall. Also, heavier or less viscous droplet exhibits higher rotational speed, which is believed to enhance oscillatory motion. As for the L-shaped channel, it is found that the droplet deformability can help to avoid the droplet from impacting upon the channel wall.