Numerical simulation of evaporating capillary jets

Abstract

A detailed numerical study of evaporating capillary jets is presented. The analysis is performed through use of a Galerkin finite element method with penalty formulation for solving the equations of motion and a flux method for tracking the free surface. A parametric study is performed to analyze the temporal instability of the evaporating jet. Through varying the evaporation rate, Reynolds number, disturbance wave number, initial disturbance amplitude, and density ratio the outcomes of jet breakup are investigated. Also, pressure distribution inside the jet and multiple satellite drop formations are analyzed. Results are compared to existing analytical conclusions made from linear stability analysis. This study reveals that surface evaporation has a destabilizing effect for the low speed jets, which are considered here. That is, evaporation flux is greater at the neck than the crest, which accelerates the wave growth. Satellite drops also reduce in size as evaporation rate is increased. This reduction is seen in both the radial direction due to vapor leaving the surface and along the axis of symmetry due to decreased breakup time