Secondary atomization of water-in-oil emulsion drops impinging on a heated surface in the film boiling regime

Maxim Piskunov, Jan Breitenbach, J. Benedikt Schmidt, Pavel Strizhak, Cameron Tropea, Ilia V. Roisman

Research output: Contribution to journalArticlepeer-review

Abstract

The present study experimentally examines the secondary atomization arising from the impingement of a water-in-oil emulsion drop onto a hot sapphire glass surface. The main aim of this study is to characterize secondary droplets emerged from the rim and lamella disruption. Drop impacts of n-dodecane and emulsions with a water volume content of 1.98%, 4.95%, 9.90% and 19.80% have been observed using a high-speed video system. The impact velocity and the target initial temperature have been varied. It is shown that the maximum spreading diameter of the impinging drop, the typical dimensionless diameter of the secondary drops, as well as the number of secondary drops correlate well with the Weber number for a pure liquid. Corresponding scaling relations Dmax∼D0We1/2, D32∼D0We−1/2 and N∼We3/2 in the limit We≫1 are derived by considering the dynamics of spreading and breakup. The size of the secondary drops is reduced significantly for high emulsion concentrations. This effect is explained by the stabilizing role of the water drops in the emulsion, whose surface tension is much higher than the surface tension of the bulk liquid.

Original languageEnglish
Article number120672
JournalInternational Journal of Heat and Mass Transfer
Volume165
DOIs
Publication statusPublished - Feb 2021

Keywords

  • Drop impact
  • Emulsion
  • Film boiling
  • Long-wave Marangoni instability
  • Rayleigh-Taylor instability
  • Secondary atomization

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Fingerprint Dive into the research topics of 'Secondary atomization of water-in-oil emulsion drops impinging on a heated surface in the film boiling regime'. Together they form a unique fingerprint.

Cite this