Experimental Investigations of Effervescent Atomization Using Non-intrusive Techniques

journal article - other

English

Although effervescent atomizers (twin fluid atomizers with internal mixing) represent one of the most recent atomization techniques, they have already shown great usability especially in combustion applications. Due to their different drop formation mechanism they are able to produce smaller droplets than many other conventional atomizers at similar operating conditions, thus making the combustion process more efficient. However, one of the shortcomings of effervescent atomization is the complexity of the atomization mechanism, which involves a two-phase flow. This complexity presents a challenging obstacle when trying to devise computational models describing effervescent sprays. In the past few years many various models have been proposed, but their verification and validation often relies only on very limited data, such as only few representative diameters. The purpose of this paper is to review the previous experimental studies on effervescent atomization in order to identify areas that need to be more deeply investigated. The parameters that need more detailed analysis include especially radially (or angularly) and axially dependent representative drop diameters or drop distributions and mass fluxes. It is shown that previous measurements did not collect sufficient amount of data across the whole spectrum of drop sizes and thus parts of the previously measured spectra might be unreliable. A methodology for effervescent spray measurement for verification and validation of numerical models for combustion applications is suggested. A possible need of blending drop size distribution functions from multiple measurements is also highlighted.

effervescent spray, experiment, PDA

BROUKAL, J.; HÁJEK, J.; SOJKA, P.

2013

30. 9. 2013

AIDIC Servizi S.r.l.

Milano, Italy

1974-9791

Chemical Engineering Transactions

35

1

Republic of Italy

1135

1140

6