Hierarchical instability of a vortex ring array in multipulse laser-matter interactions

Stjepan Lugomer, Yasuhide Fukumoto

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

In XeCl excimer Laser interactions with Co-coated steel surfaces, we have seemingly realized a quasi-linear array of vortex rings. These form from instabilities on an array of vortex filaments which emerge and then lead to a series of loops. Finally the collapse-and-reconnection process yields a cascade of nearby vortex rings. Since the filament array is subjected to randomly distributed local multipolar strains, unstable waves can develop on the vortex rings. These deformed shapes are frozen permanently by ultrafast cooling, following the last laser pulse. Using a modal analysis, an attempt is made to relate the wave structures to a parametric resonance instability which is caused by dipolar and a quadrupolar fields. Multipulse laser-matter interactions are thus capable of nonselective excitation of vortex ring instabilities of various sizes and various modal structures.

Original languageEnglish
Pages (from-to)277-290
Number of pages14
JournalFluid Dynamics Research
Volume36
Issue number4-6
DOIs
Publication statusPublished - Apr 1 2005

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All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Physics and Astronomy(all)
  • Fluid Flow and Transfer Processes

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