Open AccessInstantaneous one-dimensional equivalence ratio measurements in methane/air mixtures using femtosecond laser-induced plasma spectroscopy
Author(s) -
Dayuan Zhang,
Qiang Gao,
Bo Li,
Zhifeng Zhu,
Zhongshan Li
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.002159
Subject(s) - optics , spectroscopy , femtosecond , turbulence , materials science , laminar flow , laser , supercontinuum , plasma , physics , analytical chemistry (journal) , atomic physics , chemistry , optical fiber , photonic crystal fiber , chromatography , quantum mechanics , thermodynamics
Equivalence ratio is one of the most significant parameters in combustion flow fields. In this paper, femtosecond laser-induced plasma spectroscopy (FLIPS) technique for instantaneous one-dimensional local equivalence ratio measurements were performed. By measuring the spatially resolved spectra of FLIPS, we found that the spectral peak area ratios of CH (431 nm)/N 2 (337 nm), CH (431 nm)/N 2 (357 nm), and CH (431 nm)/O (777 nm) can be utilized to achieve one-dimensional local equivalence ratio measurements. Among them, the CH peak at ~431 nm and the O peak at ~777 nm are strong enough to be used to achieve single-shot measurements, which is important to turbulent flow fields. Furthermore, systematic experiments were performed by using FLIPS in both laminar and turbulent flow fields. The FLIPS technique features the abilities of instantaneous one-dimensional quantitative measurements, high spatial resolution, and no Bremsstrahlung interference.