PREDICTING DROP SIZE DISTRIBUTIONS FROM FIRST PRINCIPLES FOR NON-NEWTONIAN FLUIDS

An analytical method for predicting drop size distributions in sprays where primary atomization dominates has been applied to non-Newtonian (viscoelastic) fluids. The method is based on an application of the discrete probability function (DPF) technique to an existing instability analysis of a viscoelastic jet. In the present work, drop size distributions produced by an effervescent atomizer spraying single-phase viscoelastic fluids are predicted. The effect of fluctuations in fluid physical properties (relaxation time, zero shear viscosity, and surface tension), two-phase flow parameters (interphase velocity slip ratio), and atomizer operating parameters (ALR) is reported. The effect of one and two simultaneously fluctuating parameters on the drop size distribution is investigated. The results indicate that ALR and interphase velocity slip ratio, rather than liquid physical properties, have the most significant effect on the drop size distribution.