Filamentary anemometry using femtosecond laser-extended electric discharge - FALED

Research output: Contribution to journalArticle

Abstract

We demonstrate a non-contact spatiotemporally resolved comprehensive method for gas flow velocity field measurement: Filamentary Anemometry using femtosecond Laser-extended Electric Discharge (FALED). A faint thin plasma channel was generated in ambient air by focusing an 800-nm laser beam of 45 fs, which was used to ignite a pulsed electric discharge between two electrodes separated over 10 mm. The power supplier provided a maximum voltage up to 5 kV and was operated at a burst mode with a current duration of less than 20 ns and a pulse-to-pulse separation of 40 μs. The laser-guided thin filamentary discharge plasma column was blowing up perpendicularly by an air jet placed beneath in-between the two electrodes. Although the discharge pulse was short, the conductivity of the plasma channel was observed to sustain much longer, so that a sequence of discharge filaments was generated as the plasma channel being blown up by the jet flow. The sequential bright thin discharge filaments can be photographed using a household camera to calculate the flow velocity distribution of the jet flow. For a direct comparison, a flow field measurement using FLEET [Michael, Appl. Opt. 50, 5158 (2011)] was also performed. The results indicate that the FALED technique can provide instantaneous nonintrusive flow field velocity measurement with good accuracy.

Details

Authors
  • Bo Li
  • Yifu Tian
  • Qiang Gao
  • Dayuan Zhang
  • Xiaofeng Li
  • Zhifeng Zhu
  • Zhongshan Li
Organisations
External organisations
  • Tianjin University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Fusion, Plasma and Space Physics
Original languageEnglish
Pages (from-to)21132-21140
Number of pages9
JournalOptics Express
Volume26
Issue number16
Publication statusPublished - 2018 Aug 6
Publication categoryResearch
Peer-reviewedYes