Theoretical analysis of Rayleigh–Taylor instability on a spherical droplet in a gas stream

Yikai Li, Peng Zhang, Ning Kang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

4 Citations (Scopus)

Abstract

A linear analysis of the Rayleigh–Taylor (R–T) instability on a spherical viscous liquid droplet in a gas stream is presented. Different from the most previous studies in which the external acceleration is usually assumed to be radial, the present study considers a unidirectional acceleration acting on a spherical droplet with arbitrary initial disturbances and therefore can provide insights into the influence of R–T instability on the atomization of spherical droplets. A general recursion relation coupling different spherical modes is derived and two physically prevalent limiting cases are discussed. In the limiting case of inviscid droplet, the critical Bond numbers to excite the instability and the growth rates for a given Bond number are obtained by solving two eigenvalue problems. In the limiting case of large droplet acceleration, different spherical modes are asymptotically decoupled and an explicit dispersion relation is derived. For given Bond number and Ohnesorge numbers, the critical size of stable droplet, the most-unstable mode and its corresponding growth rate are determined theoretically.

Original languageEnglish
Pages (from-to)634-644
Number of pages11
JournalApplied Mathematical Modelling
Volume67
DOIs
Publication statusPublished - 1 Mar 2019

Keywords

  • Linear analysis
  • Non-radial acceleration
  • Rayleigh–Taylor instability
  • Secondary atomization
  • Spherical droplet

ASJC Scopus subject areas

  • Modelling and Simulation
  • Applied Mathematics

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