Computations of Compound Droplet Formation from a Co-axial Dual Nozzle by a Three-Fluid Front-Tracking Method

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Jiro Koga¹  Taeseon Kim¹  Kouta Moriguchi¹  Shunji Homma¹ 

[1] Division of Materials Science, Graduate School of Science and Engineering, Saitama University

关键词: Compound Droplets;    Navier–Stokes Equations;    Flow-Focusing Device;    Front-Tracking Method;   

DOI  :  10.1252/jcej.13we125

来源: Maruzen Company Ltd

【 摘 要 】

References(14)Cited-By(1)Formation of compound droplets from a co-axial dual nozzle was simulated by a three-fluid front-tracking method. The device simulated in this study is the so-called flow-focusing device. Core and shell fluids, which are the constituents of a compound droplet, are injected from inner and outer nozzles, respectively. External fluid is also injected to drag the core and shell fluids and promote their breakup into droplets. The dripping–jetting transition was observed in a manner similar to the formation of simple droplets in two-fluid systems. The formation of compound droplets sometimes fails, and simple droplets with no core fluid are produced depending on the non-dimensional numbers. The transition between compound and simple droplets was examined by changing the Capillary number (Ca) of the core fluid and the ratio of the external fluid viscosity to the droplet fluid viscosity. When both the viscosity ratio and Ca are low, the droplets break off as simple droplets. When these numbers are moderate, compound droplets are formed. The Weber number of the core fluid also influences the formation of compound droplets.

【 授权许可】

Unknown