Transient Processes of Liquid Breakup under Interaction of Multiple-Jets Configuration

Abstract

This paper describes the transient processes of the micro-liquid jets under the interaction of the multiple jet configurations. The micro-liquid jets are injected from an orifice plate with different diameters of the orifices. The size of the orifice plate is 5000μm and the diameters of the orifices are 100μm and 200μm, respectively. There are orifices on the orifice plate with pitch-to-diameter ratios ranging from 2 to 10. The evolution of the micro liquid jets during the break-up processes was observed using IDT-high speed video camera. Results showed the evolution of the instability modes of the liquid jets of same diameter changes as the Reynolds number increased. The liquids first formed a meniscus around the outlet of the larger orifice because of the stronger effects of the surface tension associated the micro-jet. The meniscus was transformed to the spherical and elliptical shapes as the inertia of the liquid was increased with time. Finally it became a steady liquid jet. Results also showed the evolution of instability modes of the liquid jets as the pressure was increased. The instability modes of both liquid jets can be described by three different modes, including the axisymmetric mode, helical mode and combined mode. Results reveal that the pitch between two different orifices is a major factor having influence on the formation of jets. It is also found that there is a time lag between the liquid jets issued from different orifices and the time lag increases as the pitch between orifices is increased.