Dual-laser-induced breakdown thermometry via sound speed measurement: A new procedure for improved spatiotemporal resolution

Research output: Contribution to journalArticle

Abstract

Measurement of acoustic waves from laser-induced breakdown has been developed as gas thermometry in combustion atmospheres. In the measurement, two laser-induced breakdown spots are generated and the local gas temperature between these two spots is determined through the measurement of the sound speed between them. In the previous study, it was found that the local gas breakdown can introduce notable system uncertainty, about 5% to the measured temperature. To eliminate the interference, in present work, a new measurement procedure was proposed, where two individual laser pulses with optimized firing order and delay time were employed. With the new measurement procedure, the system uncertainty caused by local gas breakdown can be largely avoided and the temporal and spatial resolutions can reach up to 0.5 ms and 10 mm, respectively. The improved thermometry, dual-laser-induced breakdown thermometry (DLIBT), was applied to measure temperatures of hot flue gases provided by a multijet burner. The measured temperatures covering the range between 1000 K and 2000 K were compared with the ones accurately obtained through the two-line atomic fluorescence (TLAF) thermometry with a measurement uncertainty of ~3%, and a very good agreement was obtained.

Details

Authors
Organisations
External organisations
  • Shanghai Jiao Tong University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics
  • Fluid Mechanics and Acoustics

Keywords

  • Combustion atmosphere, Dual-laser-induced breakdown thermometry, High-temperature measurement, Laser-induced acoustic measurement of acoustic wave
Original languageEnglish
Article number2803
JournalSensors (Switzerland)
Volume20
Issue number10
Publication statusPublished - 2020 May 14
Publication categoryResearch
Peer-reviewedYes