An experimental investigation on the disintegration of circular liquid jets, ejected into a stagnant ambient atmosphere at low Weber number, is presented in this thesis. The process of breakup of the liquid jet was captured using a real-time image processing high-speed digital camera system. In order to understand the influence of inertial, surface tension, and viscous forces on the process of breakup, a range of Weber numbers from 5 to 110 was experimentally tested. A syringe pump was used to provide a constant flow rate and produce a jet at a given Weber number. The effects of surface tension and viscosity were investigated by using two viscous liquids (ethylene glycol and propylene glycol) apart from water. Nozzle diameters from 0.279 mm to 1.753 mm were used to study its influence on the liquid jet breakup.
Results show that the jet breakup patterns for water at lower Weber numbers follow a different behavior than that for higher Weber numbers. In the former case, the breakup length depends not only on Weber number, but also quite significantly, on nozzle exit diameter. Moreover the functional dependence of jet breakup length in this range (We < 100), besides inertia and surface tension, is also governed by viscous and gravitational forces. The influence of liquid properties and nozzle diameter on jet breakup is discussed along with a parametric scaling of the different forces. A universal correlation to depict the breakup in any Newtonian liquid is established. The influence of elongational viscosity on the breakup of low Weber number large diameter jets is discussed along with the experimental findings.