Numerical Simulation of Two-Phase Flow in an Effervescent Atomizer

The main concern of atomization is to have a
controllable and uniform spray. In suspension plasma
spraying technique, there is a vital demand to
produce a uniform and non-pulsating spray.
Effervescent atomizers, in which a gas is bubbled
into the bulk liquid through an aerator, have shown
to be a technological alternative to the conventional
atomizers when atomization of liquids with large
variety of viscosity and density is required. Thus,
understanding the behavior of gas and liquid flow
through the nozzle is crucial to predict the
condition of outcoming spray. In this study, the
two-phase flow inside the effervescent atomizers is
numerically modeled. The behavior of liquid film in
the discharge passage is investigated using different
Gas to Liquid mass flow Ratios (GLR). These numerical
results are compared with the experimental data
available in literature. The effect of nano-sized
solid particles concentration on the liquid film
thickness at the exit of the atomizer is studied
through the change in liquid bulk density and viscosity.

Autorentext

Sanaz is a research assistant and PhD student at University ofToronto,collaborating with Université de Sherbrooke on modelinglarge-scale carbon nanotube production.She pursued her MScstudies in the CFD lab at Concordia University_ Montréal. HerM.Sc studies involved the numerical investigation of two-phaseflow inside the effervescent atomizers.

Klappentext

The main concern of atomization is to have acontrollable and uniform spray. In suspension plasmaspraying technique, there is a vital demand toproduce a uniform and non-pulsating spray.Effervescent atomizers, in which a gas is bubbledinto the bulk liquid through an aerator, have shownto be a technological alternative to the conventionalatomizers when atomization of liquids with largevariety of viscosity and density is required. Thus,understanding the behavior of gas and liquid flowthrough the nozzle is crucial to predict thecondition of outcoming spray. In this study, thetwo-phase flow inside the effervescent atomizers isnumerically modeled. The behavior of liquid film inthe discharge passage is investigated using differentGas to Liquid mass flow Ratios (GLR). These numericalresults are compared with the experimental dataavailable in literature. The effect of nano-sizedsolid particles concentration on the liquid filmthickness at the exit of the atomizer is studiedthrough the change in liquid bulk density and viscosity.