Effect of drainage device on the transition of dripping and jetting modes

Abstract

The formation of droplets is a part of many practical engineering problems. Satellite droplets are harmful in the production of traditional Chinese medicines, ink-jet printing, and electronic packaging. It is necessary to investigate the methods to eliminate the satellite droplets. A drainage device was added to the dropper to suppress the formation of satellite droplets. This paper investigated the effects of liquid physical parameters and drainage devices on the fracture length of the neckline and the main-droplet diameter. The effect of the diversion device on the ligament was analyzed using the scaling theories of the Pinch-Off. The effect of the drainage device on the transition of the fluid from the dripping mode to the jetting mode was also investigated. After adding the drainage device, the fracture length of the neckline, the main-droplet diameter, and the number of satellite droplets are significantly reduced. The fracture length of the neckline and the main-droplet diameter decreased with the increase in the length and diameter of the drainage, but the fracture length increased with the increase in liquid depth. With the rise of glycerin mass fraction, the fracture length of the neckline increases, whereas the main-droplet diameter decreases.